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Ambulatory health care visits among active component members of the U.S. Armed Forces, 2025

Wed, 01 Jul 2026 00:00:00 Z

What are the new findings?

In 2025, U.S. active component service members (ACSMs) completed 17,478,210 ambulatory, or outpatient, visits for health care, yielding an annual rate of 13.7 visits per person-year (p-yr). Over the previous 4 years the rate of ambulatory health care encounters steadily declined, driven primarily by sharp post-pandemic reductions in COVID-19 and ‘other’ administrative health care encounters. Five major categories of diagnosis from ACSM ambulatory care visits in 2025 accounted for almost four-fifths (79.6%) of all ACSM outpatient care: musculoskeletal system diseases, ‘other’ (administrative) encounters, mental health disorders, nervous system and sensory organ diseases, and symptoms, signs and ill-defined conditions; this is consistent with previous years. While the most frequent diagnoses of specific conditions for both male and female ACSMs were joint pain, lower back pain, and adjustment disorders, men had higher rates of sleep apnea and alcohol dependence, while women had higher rates of generalized anxiety and anemia due to iron deficiency.

What is the impact on readiness and force health protection?

The operational burdens of mental health and musculoskeletal disorders pose a critical challenge to force readiness, as these chronic conditions both directly degrade individual deployability and require sustained, resource-intensive medical care. The sex disparity in care provision compounds this challenge, as service women receive ambulatory care for illnesses and injuries at a rate 62.8% higher than service men. Addressing these shared leading diagnoses alongside sex-specific health care needs will be vital for optimizing medical resource allocation, improving military health system capacity, and sustaining overall force readiness.

Background

This report documents the frequencies, rates, trends, and characteristics of ambulatory, or outpatient, health care visits in 2025 of active component members of the U.S. Army, Navy, Air Force, Marine Corps, and Space Force. Ambulatory hospital and clinic visits by U.S. service members in fixed military and non-military (reimbursed through the Military Health System) facilities are documented by standardized records that are routinely archived in the Defense Medical Surveillance System (DMSS) for health surveillance purposes. Ambulatory visits not routinely and completely documented within fixed military and non-military hospitals and clinics (e.g., during deployments, field training exercises, or at sea) are not included in this analysis.

As in prior MSMR reports, all records of ambulatory health care visits by active component service members (ACSMs) were categorized according to the International Classification of Diseases, 10th Revision (ICD-10) codes entered in the primary (i.e., first-listed) diagnostic position of the visit records. Incidence rates were calculated per 1,000 person-years (p-yrs). Percent change in incidence was calculated using unrounded rates.

Frequencies, rates and trends

In 2025, U.S. ACSMs completed 17,478,210 ambulatory visits for medical care, resulting in an unadjusted annual rate—for all causes—of 13,674.4 visits per 1,000 p-yrs, or 13.7 visits per p-yr (Table 1). The observed rate represents an 8.3% decrease compared to 2024. Excluding the slight increase (1.6%) recorded in 2024, the rates have shown a continuous downward trend since 2021 (Figure 1). Excluding the ‘other’ major diagnostic category, there were 13,964,855 documented ambulatory visits for illnesses and injuries (ICD-10 A00–T88, including relevant pregnancy ‘Z’ codes) in 2025, corresponding to an unadjusted rate of 10.9 visits per p-yr, which is 6.3% lower than in 2023 (11.7 per p-yr) and 9.0% higher than in 2021 (10.0 per p-yr).

A ‘Z’ code in the first diagnostic position identifies administrative visits within the ‘other’ category for visits related to other factors influencing health status and contacts with health services (excluding pregnancy). After a sharp decline (55.7%) observed for Z-coded encounters from 2021 to 2023, in 2025 the frequency remained relatively stable, with only an 8.5% rate decrease compared to 2023 (Table 1).

Ambulatory visits, by ICD-10 major diagnostic categories

The leading 5 major diagnostic categories in 2025 remained consistent, accounting for almost four-fifths (79.6%) of all ambulatory visits among ACSMs. Musculoskeletal system and connective tissue disorders (26.8%) were the leading category in 2025, surpassing ‘other’ (20.1%), which was the dominant category in 2021. Mental health disorders (15.0%); disorders of the nervous system and sensory organs (9.8%); and symptoms, signs, and ill-defined conditions (7.8%) maintained stable rankings (Table 1). Rankings for other diagnostic categories were also largely stable.

From 2021 through 2025, the categories of ‘other’, pregnancy and delivery, infectious and parasitic diseases, and COVID-19 exhibited a continuous downward trend, while the categories of skin and subcutaneous tissue diseases and endocrine, nutritional and metabolic diseases as well as categories both continuously increased. The remaining categories exhibited fluctuating patterns. The COVID-19 diagnostic category demonstrated the largest decline in both numbers and rates, with the rate of visits decreasing by 91.3%, followed by ‘other’ (-59.5%), infectious and parasitic diseases (-16.5%), and pregnancy and delivery (-2.3%).

In a departure from last year’s findings,¹ mental health disorders evinced the highest growth rate during the prior 5 years, rather than musculoskeletal system diseases. Ambulatory visits for mental health-related disorders increased by 260,248 visits (a growth rate of 15.9%), followed by musculoskeletal system diseases, which recorded an increase of 200,551 visits (a growth rate of 9.1%). With the exception of endocrine, nutritional and metabolic diseases, which increased by 47.8%, all other categories with rises in rates exhibited rate increases within the range of 2.6–27.8% (Figure 3).

Ambulatory visits, by sex

For both male and female ACSMs, joint pain contributed to over 44% of all musculoskeletal system diseases category diagnoses. Adjustment disorder was the leading diagnosis in the mental health category for both men and women, representing approximately 20% of mental health diagnoses for both sexes (Tables 2, 3). “Anemia, unspecified” emerged as the most frequent diagnosis among service men within the major diagnostic category of blood and immune disorders, accounting for 19.6% of ambulatory visits by male ACSMs; conversely, “iron-deficiency anemia, unspecified” was the most frequent diagnosis among service women, accounting for 32.2% of their outpatient visits (Tables 2, 3). Unspecified viral infection and unspecified acute upper respiratory infection were the leading diagnoses in 2025 for infectious and parasitic diseases and diseases of the respiratory system, respectively, in both men and women (Tables 2, 3).

In 2025, service men accounted for nearly three-fourths (71.3%) of all illness- and injury-related visits, but excluding ‘other’ diagnoses, the annual rate (17.2 visits per p-yr) of all encounters for service women was 79.9% higher than among service men (9.5 visits per p-yr) (data not shown). Excluding pregnancy and delivery visits, which accounted for 9.5% of all non-Z-coded (‘other’) ambulatory visits among service women, the illness and injury ambulatory visit rate was 15.5 visits per p-yr, 62.8% higher than among service men.

Rates of illness- and injury-specific diagnoses among service women exceeded male rates by over 50% in all major diagnostic categories except diagnoses for nervous system and sensory organ diseases, circulatory system diseases, digestive system diseases, and injury (data not shown). Female rates were more than twice male rates for blood and immune diseases, mental health disorders, genitourinary system diseases, COVID-19, and endocrine, nutritional and metabolic diseases.

Relationships between age group and ambulatory visit rates were broadly similar among men and women within all diagnostic categories (Figure 2). Ambulatory rates for musculoskeletal system diseases, neoplasms, nervous system and sensory organ diseases, digestive system diseases, circulatory system diseases, and endocrine, nutritional and metabolic diseases rose more steeply with advancing age than other categories of illness or injury (Figure 2).

Seven of the 10 leading diagnoses during ambulatory visits were the same for male and female service members: pain in joint; low back pain; adjustment disorders; pain in limb, hand, foot, fingers or toes; post-traumatic stress disorder (PTSD); sleep apnea; and encounter for issue of medical certificate. Sleep apnea was the second-most frequent illness- or injury-specific primary diagnosis for men, while ninth for women. The difference in the rate rank order of mental health disorders is also worth noting. Alcohol dependence was the eighth most frequent diagnosis for men but was not identified among the leading 10 causes of ambulatory visits for women, while generalized anxiety disorder, anxiety disorder (unspecified), and cervicalgia were among the 10 most common diagnoses for women (Tables 2, 3).

Discussion

In 2025, ambulatory health care visits among active component service members (ACSMs) decreased by 8.3% compared to 2024, declining to 13.7 visits per person-year (p-yr)—the lowest level since the 2021 peak. This overall decline was largely driven by a continuous downward trend in 4 major diagnostic categories: ‘other’ administrative encounters, pregnancy and delivery, infectious and parasitic diseases, and COVID-19. The rate of encounters for COVID-19, which peaked in 2021, declined to last place in 2025, correlating to the waning of the pandemic.

Despite these declines in ambulatory visits, the unadjusted annual rate of visits for illness- and injury-related conditions among ACSMs remains elevated, at 13.4 visits per p-yr, far exceeding the rate among civilian adults ages 18-44 years: 324.6 visits per 1,000 persons, or approximately 0.3 visits per p-yr.² This elevated rate of ambulatory care visits by ACSMs underscores the intense physiological demands of military service. Future analyses comparing specific major diagnostic category rates to civilian counterparts may help further elucidate these medical costs of readiness.

Analysis of illness- and injury-specific health care encounters among ACSMs by sex reveals marked differences: Female service members receive outpatient care at nearly double the rate of male service members (17.2 vs. 9.5 visits per p-yr, respectively). This difference aligns with data from the 2022 National Ambulatory Medical Care Survey, which indicates that civilian women procure health care services at approximately 1.8 times the rate of civilian men.2 Within the U.S. military, female ACSM health care encounter rates in specific diagnostic categories were more than double those of male ACSMs, including blood and immune diseases, mental health disorders, and endocrine, nutritional and metabolic diseases.

While joint pain and adjustment disorders remain the leading diagnoses for both sexes throughout the U.S. Armed Forces, distinct secondary health risks highlight need for nuanced, targeted interventions. Men exhibit a high prevalence of sleep apnea (their second-most frequent illness-specific diagnosis) and alcohol dependence, contrasting with significantly higher rates of generalized anxiety and cervicalgia among women. Addressing these shared occupational burdens along with sex-specific diagnostic trends will be critical for optimizing military health system capacity.

Several limitations should be considered when interpreting these findings. Unit level ambulatory care, care by non-credentialed providers (e.g., medics, corpsmen), and at deployed medical treatment facilities (including ships at sea) were not included. This summary does not reflect the fact that the types and rates of illnesses and injuries may vary between deployed and non-deployed ACSMs.

This summary is based on primary (i.e., first-listed) diagnosis codes reported on ambulatory visit records; the current summary discounts morbidity related to co-morbid and complicating conditions that may have been documented in secondary diagnostic positions of health care records. The accuracy of reported diagnoses likely varies according to medical condition, clinical setting, care provider, and treatment facility, as diagnostic information is collected for non-surveillance purposes. Although specific diagnoses during individual encounters were potentially not definitive, final, or even correct, summaries of the frequencies, trends, and natures of ambulatory health care encounters among ACSMs provide descriptive evidence to inform further research and evaluation.

Rates and frequencies reported do not reflect unique individuals, but a rate of total ambulatory visits per person-year. The data presented in this report were extracted from DMSS on May 1, 2026. This report documents all ambulatory health care visits but does not estimate incidence rates for the diagnoses described. These data provide descriptors of health care provision, which elevate rates for disorders requiring increased numbers of ambulatory visits. In contrast to common, self-limited, and minor illnesses and injuries that require little, if any, follow-up or continuing care, illnesses and injuries necessitating multiple ambulatory visits for evaluation, treatment, and rehabilitation are over-represented in this summary.

References

Armed Forces Health Surveillance Division. Ambulatory health care visits among active component members of the U.S. Armed Forces, 2023. MSMR. 2024;31(6):19-25. Accessed Aug. 21, 2025. https://www.health.mil/news/articles/2024/06/01/msmr-ambulatory-care-2023
Santo L, Peters ZJ, Guluma L, Ashman JJ. Visits to health centers among adults, by selected characteristics: United States, 2022. Natl Health Stat Report. 2024;22(211):cS353454. doi:10.15620/cdc/59282

Absolute and relative morbidity burdens attributable to various illnesses and injuries among active component members of the U.S. Coast Guard, 2025

Wed, 01 Jul 2026 00:00:00 Z

What are the new findings?

In 2025, injuries, mental health disorders, and musculoskeletal system diseases were the categories of medical conditions associated with the most medical encounters, greatest numbers of members affected, and largest numbers of hospital days among active duty U.S. Coast Guard members. The morbidity burdens of Coast Guard members in 2025 are similar to those reported for Department of War active component service members. Mental health diagnoses, particularly mood and substance abuse disorders, in 2025 disproportionately accounted for more than half of all hospital bed days of Coast Guard members.

What is the impact on readiness and force health protection?

The concentrated morbidity burden for mental health disorders, injuries, and musculoskeletal conditions may degrade the operational readiness of the Coast Guard by removing its members from duty for extended inpatient treatment and prolonged recovery periods. This dual burden emphasizes the physical and psychological demands placed on U.S. Coast Guard personnel and indicates critical areas where preventive health measures could substantially improve mission readiness and reduce lost duty time.

Background

Operating under the authority of the U.S. Department of Homeland Security, the U.S. Coast Guard is a branch of the military tasked with maritime safety, law enforcement, and environmental protection, as well as support of naval operations.^1,2 As the second smallest branch of the U.S. Armed Forces, comprising roughly 47,568 active component members, the Coast Guard is the sole military service functioning outside the direct purview of the Department of War (DOW).

While Coast Guard personnel are authorized to access Military Health System (MHS) hospitals and clinics, their bases are often not located near MHS facilities. Consequently, the Coast Guard maintains its own network of clinics in high Coast Guard-population areas, but those facilities are strictly limited to primary care.¹ This structural limitation contributes to significant health care access challenges for Coast Guard beneficiaries—including active duty members, eligible reservists, retirees, and dependents. Recent assessments of Coast Guard health care provision have underscored systemic issues such as clinic staffing deficits and critical data gaps, among others.¹

In recent years, missing and disparate data that precluded comprehensive Coast Guard morbidity surveillance led to its excision from MSMR annual morbidity burden analyses from 2016 through 2021.^3,4 A 2021 report on Coast Guard active duty hospitalizations underscored those data issues, reporting a 40% lower observed hospitalization rate than among DOW active component service members.³ To address those gaps in the data and ensure continuous, reliable morbidity surveillance, in 2022 MSMR reinstated separate analyses for the Coast Guard. This report employs the standardized disease classifications and morbidity burden methodologies established for the greater U.S. Armed Forces to quantify the health impacts of various illnesses and injuries on the Coast Guard’s active component in 2025.

Methods

The population for this analysis included all individuals who served in the active component of the U.S. Coast Guard at any time during the surveillance period of January 1, 2025 through November 30, 2025. The methodology used to determine the absolute and relative morbidity burdens for the Coast Guard active component in 2025 is identical to the approach described on page 5 of this issue for the greater U.S. Armed Forces.

Results

In 2025, a total of 37,477 Coast Guard service members required 475,658 total medical encounters, which included 9,695 reported hospital bed days, with a rate of 0.26 hospital bed days per Coast Guard member who received either outpatient or inpatient medical care in 2025.

Morbidity burden, by category

In 2025, injury represented the leading cause of all medical encounters for the Coast Guard active component, affecting 17,034 service members (Figure 1a). In addition to driving 22.0% of all medical encounters, injuries ranked third overall in total hospital bed days (Figure 1b).

Mental health disorders accounted for more hospital bed days (n=5,444) than any other morbidity-related category, constituting over half (56.2%) of all hospital bed days and ranked fifth in terms of numbers of individuals affected (Figures 1a, 1b). Combined, injury and mental health disorders accounted for over three-fifths (63.7%) of all hospital bed days and more than two-fifths (43.4%) of all medical encounters.

Maternal conditions (pregnancy complications, delivery, all other maternal disorders, puerperium complications, and ectopic pregnancy, miscarriage, abortion), accounted for a relatively large proportion of all hospital bed days (n=1,304, 13.5%) but a much smaller proportion of total medical encounters (n=4,281, 0.9%) (Figures 1a, 1b). Maternal conditions were the most prevalent medical condition among female active component Coast Guard members. Women comprised approximately one-sixth (16.4%) of the active duty Coast Guard in 2025.

Medical encounters, by condition

In 2025, 5 disease-related conditions accounted for more than one-third (37.2%) of all illness- and injury-related medical encounters among active component Coast Guard members: anxiety disorders, other back problems (including lower back pain, other dorsalgia), organic sleep disorders (e.g., obstructive sleep apnea, insomnia), arm and shoulder injuries, and knee injuries (Figure 2). Moreover, the 10 conditions associated with the most medical encounters constituted more than half (58.4%) of all illness- and injury-related medical encounters.

The major category conditions in 2025 that predominantly accounted for medical encounters among active component Coast Guard members included injuries, mental health disorders, and musculoskeletal conditions. Among reported injuries, arm and shoulder (6.9%), knee (5.5%), foot and ankle (3.4%), and leg (2.5%) injuries accounted for the most medical encounters (Figure 2, Table). The 4 most frequent mental health diagnoses were for anxiety (8.9%), mood (5.0%), adjustment (4.9%), and substance abuse (1.5%) disorders. Other back problems (8.8%), all other musculoskeletal diseases (3.4%), and cervicalgia (2.1%) constituted the most medical encounters among musculoskeletal disorders. COVID-19 accounted for 0.2% of total medical encounters in 2025.

Individuals affected, by condition

The 10 categories of conditions that affected the most Coast Guard members in 2025 were all other signs and symptoms, upper respiratory infections, other back problems, refraction and accommodation, organic sleep disorders, anxiety, all other musculoskeletal diseases, all other skin diseases, arm and shoulder conditions, and respiratory and chest issues. COVID-19 affected 683 Coast Guard members, ranking fiftieth for number of individuals affected, a modest decline from thirty-sixth in 2024.

Hospital bed days, by condition

In 2025, substance abuse and mood disorders accounted for about two-fifths (45.0%) of all hospital bed days (Figure 3) among Coast Guard members. Four mental health disorders (mood, substance abuse, adjustment, anxiety) and 2 maternal conditions (pregnancy complications, delivery) combined accounted for more than three-fifths (64.8%) of all hospital bed days (Table, Figure 3). About 7.5% of all hospital bed days were attributable to injuries, declining from 12.8% in 2024.⁵ In 2025, 0.3% hospitalizations of active component Coast Guard members were due to COVID-19 (Table).

Discussion

In 2025, mental health disorders and injuries presented a major burden to force readiness and health care provision among the active component U.S. Coast Guard; together, those 2 categories accounted for nearly two-thirds (63.7%) of all hospital bed days and more than 43% of all medical encounters. This finding highlights the physical and psychological demands on Coast Guard personnel and reveals critical opportunities for targeted preventive health measures to improve mission readiness.

Musculoskeletal conditions, together with injuries, represented primary causes of ambulatory health care for Coast Guard personnel. The high prevalence of conditions affecting the back, arms, shoulders, and knees likely reflects the physically taxing nature of Coast Guard operations. Notably, more Coast Guard members were affected by other back conditions (n=7,151) than by the top-ranked injury categories of arm and shoulder (n=5,097) and knee injuries (n=4,332), underscoring the widespread impact of musculoskeletal strain.

While mental health disorders ranked fifth in the total number of individuals affected, they constituted the most severe inpatient medical burden for the Coast Guard. Specifically, conditions such as mood, substance abuse, adjustment, and anxiety disorders were responsible for over 56% of all hospital bed days. Such a disproportionate ratio suggests that when Coast Guard members require inpatient care for mental health, the acuity of those conditions necessitates extended, resource-intensive treatment. These clinical findings also align with self-reported data from the 2018 Health Related Behaviors Survey of the Coast Guard, which highlighted significant behavioral and psychological challenges for Coast Guard members: 33.9% had engaged in binge drinking in the past 30 days; 10.6% met the criteria for serious psychological distress in the past year; 4.3% needed mental health services in the past year but did not receive them; 21.9% were moderately or severely bothered by sleep-related lack of energy; 35.4% reported current tobacco or nicotine use; and 4.7% had thought about attempting suicide in the past year.⁶

This report’s findings are consistent with prior morbidity reports for active component U.S. service members, with the leading categories of medical conditions involving injury, mental health disorders, and musculoskeletal conditions.⁷ Furthermore, both Coast Guard and DOW service members shared diagnoses for many specific and prevalent conditions, including back problems, arm, shoulder and knee injuries, anxiety disorders, and organic sleep disorders. In comparison with 2025 health care encounter data for DOW active component personnel, the Coast Guard experienced a similar rate of medical encounters per person but a lower rate of hospitalization. In 2025 the Coast Guard recorded 12.7 encounters and 0.26 hospital bed days per service member, whereas the DOW reported 11.7 encounters and 0.34 bed days per service member.

In conclusion, the health of the active duty Coast Guard in 2025 was defined by the significant and sustained impact of mental health disorders, injuries, and musculoskeletal conditions. While injuries and musculoskeletal conditions drove a high volume of outpatient care, mental health disorders were the primary contributor to inpatient hospital stays, indicating a need for robust and accessible mental health services. The similarities in morbidity trends with the greater DOW underscore the shared health challenges facing the U.S. military. Future efforts to maintain force readiness should focus on targeted injury prevention programs, proactive mental health support, and ergonomic interventions to mitigate the physical and psychological stressors inherent to military service.

References

Cohen C, Chan EW, Tong PK, et al. Health Services for Coast Guard Beneficiaries: Improving Access to Care for Active Duty Service Members, Reservists, Dependents and Retirees. RAND Homeland Security Research Division, Homeland Security Operational Analysis Center;2025. Accessed Aug. 15, 2025. https://www.rand.org/pubs/research_reports/RRA3018-1.html
United States Coast Guard. U.S. Dept. of Homeland Security. Accessed Aug. 15, 2025. https://www.uscg.mil
Pillai S, Chau M, Kamara I, Thomas D, Iskander J. Hospitalizations among active duty members of the U.S. Coast Guard, fiscal year 2021. MSMR. 2023;30(2):3-5. Accessed May 15, 2026. https://www.health.mil/reference-center/reports/2023/02/01/msmr-vol-30-no-2-508
Armed Forces Health Surveillance Branch. Hospitalizations among members of the active component, U.S. Armed Forces, 2015. MSMR. 2016;23(4):8-16. Accessed Aug. 15, 2025. https://www.health.mil/reference-center/reports/2016/01/01/medical-surveillance-monthly-report-volume-23-number-4
Armed Forces Health Surveillance Division. Absolute and relative morbidity burdens attributable to various illnesses and injuries among active component members of the U.S. Coast Guard, 2024. MSMR. 2025;32(9):37-44. Accessed Jun. 17, 2026. https://health.mil/reference-center/reports/2025/09/01/msmr-vol-32-no-9-sep-2025
Pulkkinen AJ. Let’s talk about your behavioral health. My Coast Guard. U.S. Coast Guard. 2024. Accessed Aug. 15, 2025. https://www.mycg.uscg.mil/News/Article/3671040/lets-talk-about-your-behavioral-health
Armed Forces Health Surveillance Division. Absolute and relative morbidity burdens attributable to various illnesses and injuries among active component members of the U.S. Armed Forces, 2024. MSMR. 2025;32(9):4-12. Accessed Jun. 17, 2026. https://health.mil/reference-center/reports/2025/09/01/msmr-vol-32-no-9-sep-2025
World Health Organization. The Global Burden of Disease: 2004 Update. World Health Organization;2008. Accessed Aug. 14, 2025. https://www.who.int/publications/i/item/9789241563710
Murray CJL, Lopez AD, eds. The Global Burden of Disease: A Comprehensive Assessment of Mortality and Disability from Diseases, Injuries, and Risk Factors in 1990 and Projected to 2020. Harvard University Press;1996:120-122.

Surveillance snapshot: Illness and injury burdens among reserve component members of the U.S. Coast Guard, 2025

Wed, 01 Jul 2026 00:00:00 Z

Morbidity burdens attributable to various illnesses and injuries among deployed active and reserve component members of the U.S. Armed Forces, 2025

Wed, 01 Jul 2026 00:00:00 Z

What are the new findings?

In 2025, musculoskeletal system conditions were the leading cause of in-theater medical care in U.S. Africa Command (AFRICOM), U.S. Central Command (CENTCOM), and U.S. Southern Command (SOUTHCOM), while in U.S. Pacific Command (PACOM) mental health disorders were the leading cause of medical care. This year’s expanded analysis, including 4 combatant commands, of deployed service member health care, reveals that CENTCOM accounted for almost 90% of all in-theater medical encounters in 2025.

What is the impact on readiness and force health protection?

Optimization of operational readiness and the minimization of preventable lost duty time each requires the prioritization of robust, in-theater mental health assets and targeted musculoskeletal injury prevention programs. Thorough examination of the most common causes of injury and illness during deployment can assist senior leaders in developing and implementing strategies to reduce preventable medical issues, enhance force readiness, and ensure fighting strength.

Background

Each year, MSMR estimates illness- and injury-related morbidity and health care burdens within the U.S. Armed Forces and Military Health System (MHS). This report updates prior analyses of the distributions of the burdens of health care for active and reserve component service members in deployed settings. While deployed service members are selected primarily from the active component of the U.S. Armed Forces, the reserve component contributes a substantial portion of U.S. deployed forces.

This report employs data from the Theater Medical Data Store (TMDS), which documents service members’ inpatient and outpatient medical encounters during treatment in an operational environment. TMDS receives medical data from Theater Medical Information Program-Joint (TMIP-J) applications, including AHLTA-Theater (AHLTA-T), TMIP-Composite Health Care System Cache (TC2), Mobile Computing Capability (MCC), Maritime Medical Modules (MMM), and the U.S. Transportation Command Regulating and Command and Control Evacuation System (TRAC2ES).¹

While the U.S. Africa Command (AFRICOM) area of responsibility (AOR) was first included in this annual report in 2021, this year’s iteration presents the first comprehensive inclusion of 4 major geographic combatant commands. To accurately reflect the geographic distribution of U.S. force deployment, medical evacuation surveillance has expanded. In accordance with the National Defense Strategy’s focus on global strategic competition, operational tempos remain high, with U.S. forces increasingly dispersed in multiple theaters to deter aggression and build regional alliances.² Following the reduction of large-scale U.S. combat operations in the U.S. Central Command (CENTCOM) AOR in late 2021, the global geographic distribution of U.S. military operations shifted significantly, but in order to sustain counterterrorism successes, global force deployments continue to assist, advise, and accompany allied security forces.³

Methods

The surveillance population included all individuals who served in the active or reserve components of the U.S. Army, Navy, Air Force, Marine Corps, or Space Force with health care encounters captured in the TMDS during the surveillance period. Analysis was restricted to encounters where the theater of care was specified as AFRICOM, CENTCOM, U.S. Pacific Command (PACOM, formerly Indo-Pacific Command or INDOPACOM), or U.S. Southern Command (SOUTHCOM), or where the name of the theater of operation was missing or null; by default, this excluded encounters in U.S. Northern Command (NORTHCOM) and U.S. European Command (EUCOM). In addition, TMDS-recorded medical encounters where the data source was identified as Shipboard Automated Medical System (SAMS), or where the military facility descriptor indicated that care was provided aboard ship, were excluded from this analysis. Encounters from aeromedical staging facilities outside AFRICOM, CENTCOM, PACOM, or SOUTHCOM were also excluded.

Morbidity burdens attributable to various conditions were estimated by distributions of diagnoses according to the 17 traditional categories of the International Classification of Diseases (ICD) system, with an 18th category for COVID-19. Extended ICD-10 (10th Revision) code groupings were also reviewed for the most common diagnoses. The TMDS has not fully transitioned to ICD-10 codes, so some ICD-9 (9th Revision) codes were included. Primary diagnoses that did not correspond to an ICD-9 or ICD-10 code are not reported in this burden analysis.

Results

Among the 75,204 U.S. service members deployed in 2025 to AFRICOM, CENTCOM, PACOM, and SOUTHCOM, in total 172,878 medical encounters occurred. Of those documented medical encounters among deployed service members in 2025, 466 (0.27%) were recorded as hospitalizations. Most medical encounters (n=129,822, 75.0%), individuals affected (n=40,596, 80.6%), and hospitalizations (n=363, 78.0%) occurred among male service members (data not shown). In 2025, CENTCOM evinced the highest overall volume of in-theater medical encounters, far exceeding other combatant commands (Table 1), with over 152,000 total recorded diagnoses among all ICD categories. In 2025, the largest percentages of medical encounters attributed to a major ICD-10 diagnostic category were coded as musculoskeletal system diseases, followed by ‘other’ or administrative health services (‘Z’ codes, include factors influencing health status and health service contact) (Figure). The most common diagnosis within the musculoskeletal system diseases category was for lower back pain (ICD-10 code M545) (Table 2). The percentage of total medical encounters attributed to ‘other’ health services decreased from 44.0% in 2021 to 23.3% in 2025. COVID-19 accounted for only 0.2% of deployed service members’ total medical encounters in 2025.

The percentages of in-theater medical encounters attributed to musculoskeletal system diseases increased (21.1% to 31.4%) from 2021 to 2025 (Figure). Lower back pain was the most frequent ICD-10 diagnostic code (M545) for musculoskeletal disease encounters for both men and women (Table 2). The second-most frequent ICD-10 diagnostic code (M25511) for musculoskeletal medical encounters by male service members was pain in the right shoulder, while for female service members it was pain in the right knee (M25561).

The percentages of in-theater medical encounters attributed to mental health disorders increased slightly, from 4.3% to 7.3%, during the surveillance period (Figure). Adjustment disorder with mixed anxiety and depressed mood (‘F4323’) accounted for the most frequent mental health disorder diagnosis, with a slightly higher percentage of in-theater encounters for this disorder among women (2.0%) than men (1.1%) (Table 2).

While musculoskeletal system conditions ranked first in AFRICOM (35.1%), CENTCOM (31.0%), and SOUTHCOM (33.5%), mental health disorders ranked first among PACOM medical encounters (40.2%). While mental health disorders presented a notable burden elsewhere, they ranked fourth in CENTCOM (7.5%), fourth in SOUTHCOM (9.6%), and seventh in AFRICOM (4.5%). Furthermore, in PACOM physical injuries were the second-most common cause of medical encounters (15.7%), while musculoskeletal conditions—the leading cause of visits in all other regions—ranked much lower, fifth, at 5.9%. In all AORs, severe, systemic, or chronic conditions consistently ranked at the bottom of the medical encounter spectrum, confirming that the deployed environment primarily sees acute or strain-related injuries rather than chronic disease management.

Discussion

The results of this analysis of in-theater medical encounters correspond with the broader trends of medical evacuations in the U.S. military observed during the same period.⁴ In both localized clinical settings and out-of-theater evacuations, the health care burden on deployed forces is overwhelmingly caused by disease and non-battle injury (DNBI) rather than combat trauma or severe, chronic illness. Musculoskeletal conditions, particularly lower back and joint pain, consistently rank as the primary physical health challenge, precipitating both the majority of routine in-theater care as well as the need for higher-echelon medical transportation.

The highest volumes of both in-theater health care encounters and medical evacuations in 2025 were in CENTCOM,⁴ reflecting its sustained operational tempo and troop density. U.S. Pacific Command, meanwhile, presented a unique operational health profile, with mental health disorders the leading cause of both localized medical encounters and subsequent evacuations. These distinct AOR findings underscore the fact that optimization of force readiness requires differentiated and targeted approaches to force health protection. To minimize preventable personnel losses, robust musculoskeletal injury prevention programs and deployed behavioral health assets are essential to meeting the readiness demands of each combatant command.

These 2025 data also reflect a continued decline in some routine medical administration codes. In prior reports, mandatory COVID-19 screening artificially inflated the volume of ‘other’ and administrative health services. Specifically, the Z-code (Z1152) for COVID-19 screening accounted for almost 5% of all in-theater medical encounters in 20225; by 2025, this specific Z-code declined to just 0.2% of in-theater encounters.

Conditions such as diabetes, pregnancy, and congenital abnormalities often preclude deployment. Because of rigorous medical pre-screening, deployed service members may demonstrate a lower risk of conditions that could interfere with operations compared to non-deployed counterparts, drastically reducing the in-theater requirement for complex disease management.

When interpreting these results and analyses, several limitations must be considered. First, the findings in this report are derived from data extracted from the Defense Medical Surveillance System (DMSS) on May 14, 2026, and any delayed record transmissions or retrospective updates entered after that date will not be reflected. Furthermore, not all operational medical encounters are successfully recorded in TMDS. Health care provided at small, austere forward locations often precludes immediate electronic documentation. Additionally, emergency interventions required to stabilize combat-injured service members prior to rapid evacuation may bypass routine TMDS entry. Consequently, this report may underestimate the true volume of health care provided in these areas of operation. Second, as with any review relying on ICD coding, some diagnostic misclassification should be expected due to electronic health record coding errors. Although the aggregated distributions of illnesses and injuries presented in this report are compatible with assessments derived from other examinations of morbidity in military populations (both deployed and non-deployed), instances of highly unlikely diagnostic codes for a deployed population have been observed.

Finally, because this report focuses exclusively on AFRICOM, CENTCOM, PACOM, and SOUTHCOM, it does not capture medical encounters from recent troop deployments to EUCOM. Each operational theater presents a unique environment with vastly different medical assets, evacuation capabilities, and population demographics. Furthermore, person-time denominators for individuals eligible for time in-theater are not readily available. This lack of deployed person-time data prevents calculation of stratified and overall medical encounter rates for the direct comparison of populations and combatant commands.

References

Defense Health Agency. Joint Operational Medicine Information Systems Theater Medical Data Store. Fact Sheet. U.S. Dept. of War;2019. Accessed Apr. 18, 2025. https://www.health.mil/reference-center/fact-sheets/2019/07/30/tmds-fact-sheet
U.S. Department of Defense. 2022 National Defense Strategy of the United States of America. U.S. Dept. of Defense;2022. Accessed Jun. 10, 2026. https://media.defense.gov/2022/oct/27/2003103845/-1/-1/1/2022-national-defense-strategy-npr-mdr.pdf
The White House. Letter to the Speaker of the House and President pro tempore of the Senate Regarding the War Powers Report. Dec. 6, 2024. Accessed Apr. 18, 2025. https://bidenwhitehouse.archives.gov/briefing-room/statements-releases/2024/12/06/letter-to-the-speaker-of-the-house-and-president-pro-tempore-of-the-senate-regarding-the-war-powers-report-5
Armed Forces Health Surveillance Division. Medical evacuations among the active and reserve components of the U.S. Armed Forces, 2025. MSMR. 2026;33(7):33-39.
Armed Forces Health Surveillance Division. Morbidity burdens attributable to various illnesses and injuries among deployed active and reserve component service members, U.S. Armed Forces, 2022. MSMR. 2023;30(7):2-5. Accessed Jun. 23, 2026. https://www.health.mil/reference-center/reports/2023/07/01/msmr-july-2023-volume-30-issue-7

Absolute and relative morbidity burdens attributable to various illnesses and injuries among active component members of the U.S. Armed Forces, 2025

Wed, 01 Jul 2026 00:00:00 Z

What are the new findings?

In 2025, the burden of health care for U.S. service members in the active component was determined by medical diagnostic categories within a limited range: Injuries, mental health disorders, and musculoskeletal diseases accounted for the vast majority of health care provided. This concentration was most evident in ambulatory, or outpatient, care, to which only 5 specific conditions constituted one-third of all outpatient medical encounters. Inpatient treatment for mental health-related disorders comprised 51.0% of all hospital bed days for active component service member health care.

What is the impact on readiness and force health protection?

The persistent dominance of injuries, mental health disorders, and musculoskeletal diseases in Military Health System provision of care demonstrates a critical, ongoing vulnerability in force health protection that also requires sustained preventive and rehabilitative care. Addressing these outpatient and inpatient health care burdens is essential for minimizing lost duty time and optimizing the operational readiness of the force.

Background

Since 2001, MSMR has published annual reports describing the morbidity burden among U.S. military personnel,¹ using a classification system derived from the Global Burden of Disease (GBD) Study.^2,3 The GBD is a global, comprehensive epidemiological effort that systematically quantifies the magnitude of hundreds of diseases, injuries, and associated risk factors.⁴ By measuring disease incidence and prevalence in a highly standardized manner, the GBD framework establishes a vital methodological standard that enables robust health comparisons among diverse populations as well as over time.⁵

To employ the global GBD standard within a military population, MSMR adapts GBD’s operational framework to adjust for the unique occupational realities and readiness requirements of the U.S. Armed Forces. While the GBD framework relies on the International Classification of Diseases, 10th Revision (ICD-10), Clinical Modification, the standard chapter-based ICD-10 organization of more than 68,000 codes is not suitably structured for a description of specific functional burdens affecting military service members. Consequently, MSMR refines the ICD-10 code groupings into a custom framework that prioritizes the conditions and non-battle injuries with the most impacts on mission readiness.

This specialized framework is fundamentally shaped by the unique demographic composition and occupational requirements of active component service members (ACSMs). As a cohort defined by relative youth and baseline physical fitness, the force primarily consists of individuals who enlist or are commissioned between the ages of 17 and 25 years, with the vast majority concluding service by age 50 years. According to 2025 Defense Medical Surveillance System (DMSS) data, the ages 20-24 years and 25-29 years cohorts remain the largest segments of the force, while women now account for 19.9% of the active component.

Beyond these demographics, the health of the force is driven by systemic military factors that differentiate it from the general population. Rigorous pre-accession medical screening establishes a high baseline of health, while mandatory periodic health assessments facilitate the early detection and management of clinical conditions. Furthermore, the combination of high-intensity training, unique lifestyle stressors, and universal access to no-direct cost health care may concentrate morbidity within specific clinical areas. Collectively, these factors result in a morbidity profile dominated by conditions prevalent in young, physically active populations, most notably injuries, behavioral health conditions, and musculoskeletal disorders.⁶

Prior MSMR reports indicate that categories of illness and injury requiring hospitalization have historically differed from illness and injury categories that result in the most outpatient visits.^7,8 Added requirements for military readiness are likely a major factor in outpatient health care provision, but rarely for hospitalization. T he categories of medical conditions that account for the most medical encounters overall may differ from those that affect the most individuals or have the most debilitating or long-lasting effects.²

This annual summary uses 3 health care burden measures to quantify the impacts of various illnesses and injuries among members of the active component of the U.S. Armed Forces in 2025, including the total number of medical encounters, the number of individuals affected, and total hospital bed days. A consistent and comparative description of the burden of diseases and injuries, and sub-populations affected, provides valuable information to inform policy or preventive measures to sustain the medical readiness of the force.

Methods

The population for this analysis included all individuals who served in the active components of the Army, Navy, Air Force, Marine Corps, or Space Force at any time during the surveillance period of January 1, 2025 through December 31, 2025. Each service member contributed encounters and person-time only for actual months served during the surveillance period.

All data in this analysis were derived from records maintained in the DMSS, which documents both ambulatory care encounters and hospitalizations of active component members of the U.S. Armed Forces. DMSS contains all encounters in military medical and civilian treatment facilities when reimbursed through the Military Health System (MHS). Encounters not routinely and completely documented within fixed military and non-military hospitals and medical clinics (e.g., during deployments, field training exercises, or at sea) were excluded from these analyses.

DMSS data for all inpatient and outpatient medical encounters of ACSMs during the surveillance period were summarized according to the primary (i.e., first-listed) diagnosis if documented with an ICD-10 code between A00 and T88, in addition to an ICD-10 code beginning with Z37 (“outcome of delivery”) or U.S. Department of War (DOW) unique personal history codes DOD0101–DOD0105 (“personal history of traumatic brain injury”).

All illness- and injury-specific diagnoses, as defined by ICD-10 codes, are grouped into 25 burden of disease-related categories, comprising 157 medical conditions, based on a modified version of the classification system developed for the GBD Study.² This classification system was developed by the MSMR editorial staff in 2001 and is updated annually. The GBD system groups diagnoses with common pathophysiological or etiological bases or significant DOW health policy importance. In this report, some diagnoses grouped into single categories in the GBD system (e.g., mental health disorders) were disaggregated to increase military relevance. In addition, injuries are now classified by affected anatomical site rather than by cause, as external causes of injuries are not required to be documented by health care providers.

The morbidity burdens attributable to various conditions were estimated based on the total number of medical encounters associated with each condition, i.e., total hospitalizations and ambulatory visits for the condition, with a limit of 1 encounter for an individual per condition each day; and numbers of service members affected by each condition, i.e., individuals with at least 1 medical encounter for the condition during the year; as well as total bed days during hospitalizations for each condition.

Results

Morbidity burden, by category

In 2025, U.S. ACSMs (n=561,410) experienced medical encounters due to injury more than any other morbidity-related category (Figure 1a). Ranking third in terms of hospital bed days, injuries accounted for about one-tenth (10.4%) of all hospitalizations (Figure 1b). The injury category combines ICD-10 ‘S’ (“injury”) and ‘T’ codes (“burns and poisonings”), but injuries account for about 98.1% of ambulatory encounters within the category (data not shown).

Mental health disorders accounted for more hospital bed days (n=197,442) than any other morbidity-related category, contributing over half (51.0%) of all hospital bed days, ranking fifth for individuals affected (Figures 1a, 1b). Together, the injury and mental health disorder categories accounted for over two-thirds (61.4%) of all hospital bed days and 42.8% of all medical encounters in 2025.

Maternal conditions (pregnancy complications, delivery) accounted for a relatively large proportion of all hospital bed days (n=56,746, 14.7%) but a much smaller proportion of medical encounters overall (n=203,023, 1.5%) (Figures 1a, 1b). As women comprised only 19.9% of the active component in 2025, these aggregated statistics understate the impact of maternal health within the force.

Medical encounters, by condition

In 2025, almost one-third (33.3%) of all illness- and injury-related medical encounters resulted from 5 medical conditions: other back problems (lower back pain, other dorsalgia), knee injuries, arm and shoulder injuries, organic sleep disorders (insomnia, obstructive sleep apnea), and anxiety (Figure 2). Moreover, the 10 conditions associated with the most medical encounters constituted more than half (55.1%) of all illness- and injury-related medical encounters.

The categories of major medical conditions that accounted for the most health care encounters by ACSMs in 2025 were predominantly injuries, mental health disorders, and musculoskeletal diseases. The most frequent injury-related medical encounters involved the knee (6.5%), arm or shoulder (6.2%), foot or ankle (3.7%), and leg (3.2%) (Table). Mental health-related disorder diagnoses resulted most frequently from anxiety (5.9%), adjustment (4.3%), mood (4.2%), and substance abuse disorders (2.9%). Other back problems (8.6%), all other musculoskeletal diseases (4.3%), and cervicalgia (1.6%) generated the most medical encounters caused by musculoskeletal diseases. COVID-19 accounted for just 0.1% of total medical encounters by ACSMs in 2025, ranking eighty-first.

Individuals affected, by category

In 2025, the 10 categories of conditions that affected the most service members were injuries (knee, arm/shoulder); symptoms, signs, and other ill-defined conditions (all other symptoms, signs); musculoskeletal diseases (other back problems, all other musculoskeletal diseases); respiratory infections (upper respiratory infections); sensory organ diseases (refraction, accommodation); neurological conditions (organic sleep disorders); skin diseases (all other skin diseases); and respiratory diseases. COVID-19 affected 10,414 service members and ranked sixty-ninth for members affected, a considerable decrease in rank from forty-seventh in 2024.

Hospital bed days, by condition

Substance abuse and mood disorders accounted for nearly one-third (31.9%) of all hospital bed days in 2025 (Figure 3). Four mental health disorders (substance abuse, mood, adjustment, anxiety) and 2 maternal conditions (pregnancy complications, delivery) accounted for almost two-thirds (60.2%) of all hospital bed days in 2025 (Table, Figure 3). About 10.4% of all hospital bed days in 2025 were attributable to injury or poisoning. COVID-19 accounted for only 0.05% of total hospital bed days for ACSMs in 2025 (Table).

Relationships between indicators of health care

There was a strong positive correlation between numbers of medical encounters attributable to various conditions with numbers of individuals affected by those conditions (r=0.85) (data not shown). The 3 leading causes of medical encounters were among the 5 conditions that most affected individuals (Table), while weak-to-moderate positive relationships were detected between numbers of hospital bed days attributable to conditions with numbers of individuals affected by those conditions (r=0.21), or numbers of medical encounters related to a medical condition (r=0.41). For example, substance abuse disorders and labor and delivery ranked high in terms of total bed days, but these conditions had relatively small impacts on ACSMs in 2025.

Discussion

Diagnostic category conditions for injuries, mental health disorders, and musculoskeletal diseases continue to represent a collective majority of morbidity burden among ACSMs. In 2025, injuries alone surpassed 3.1 million medical encounters, representing the largest single proportion of the ambulatory care burden; this high frequency of health care provision underscores the persistent challenge of physical trauma to force health protection and readiness.

Analysis of diagnostic distributions reveals a stark divergence between ambulatory medical encounters and inpatient care requirements. While injuries command the largest share of outpatient encounters, mental health disorders impose a disproportionately higher gross burden on both inpatient resources and the force population. In 2025, mental health conditions affected nearly 275,000 ACSMs and resulted in 197,442 hospital bed days. Despite ranking second in total encounters, at approximately 2.6 million, the inpatient burden of mental health care was more than 4 times that of injuries. This disparity indicates that mental health conditions—mood disorders, adjustment disorders, and substance abuse—represent a highly intensive, long-term resource requirement for a substantial portion of the military population. Intensive inpatient provision of care contrasts with the broader, enduring operational impact of physical trauma. As a previous study reported,⁹ injuries are historically the single leading cause of death, disability, and loss of person-time among U.S. military service members. This sustained ambulatory burden is largely driven by exposure to intense physical demands during training and within operational environments, which continually increases risk of musculoskeletal injury and significant morbidity among military personnel.¹⁰

Musculoskeletal diseases also maintain a highly disproportionate impact on overall operational readiness. Ranking third in terms of total medical encounters (approximately 2.2 million encounters), musculoskeletal diseases conditions—such as back problems, knee injuries, and arm/shoulder issues—constitute a major relative share of the daily health strain on the force. While these conditions do not represent a dominant share of hospital bed days, the high volume in ambulatory settings highlights the need for continuous, rehabilitative care to ensure force readiness.

A comparison of proportional health care burdens reveals that medical resource usage remained stable between 2024 and 2025, with only a few notable shifts. In ambulatory care, the most prominent change was a proportional decrease in musculoskeletal disease encounters—falling from 17.1% in the 2024 report6 to 16.1% in 2025—concurrent with a slight increase in mental health disorder encounters (rising from 18.7% to 19.2%). Injury-related hospital bed days demonstrated the largest relative decline, dropping from 11.3% in 2024 to 10.4% in 2025. Conversely, the inpatient burden for infectious and parasitic diseases increased from 1.6% to 2.0%, and maternal conditions rose slightly, from 14.4% to 14.7%.

This analysis, like those of prior years, documents that relatively few illnesses and injury conditions account for most of the morbidity and health care burdens that affect U.S. military members. Illnesses and injuries that disproportionately contribute to morbidity and health care burdens should be high-priority targets for preventive action, research, and resources.

References

Armed Forces Health Surveillance Division. Relative burdens of selected illnesses and injuries, US Armed Forces, 2000. MSMR. 2021;7(4):20-27. Accessed May 13, 2026. https://health.mil/reference-center/reports/2001/01/01/medical-surveillance-monthly-report-volume-7-number-4
Murray CJ, Lopez AD, eds. Summary–The Global Burden of Disease: A Comprehensive Assessment of Mortality and Disability from Diseases, Injuries, and Risk Factors in 1990 and Projected to 2020. Global Burden of Disease and Injury Series. World Health Organization, World Bank, Harvard School of Public Health;1996. Accessed May 13, 2026. https://iris.who.int/server/api/core/bitstreams/c5373052-8bac-47bf-a599-45c14cbf4745/content
World Health Organization. The Global Burden of Disease: 2004 Update. World Health Organization;2008. Accessed May 13, 2026. https://www.who.int/publications/i/item/9789241563710
Hay S, Ong K, Santomauro D, et al. Burden of 375 diseases and injuries, risk-attributable burden of 88 risk factors, and healthy life expectancy in 204 countries and territories, including 660 sub-national locations, 1990–2023: a systematic analysis for the Global Burden of Disease Study 2023. Lancet. 2025;406:1873-1922. doi:10.1016/s0140-6736(25)01637-x
Global Burden of Disease Collaborative Network. Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) Protocol. Institute for Health Metrics and Evaluation. Updated Jun. 4, 2024. Accessed May 14, 2026. https://www.healthdata.org/research-analysis/about-gbd/protocol
Armed Forces Health Surveillance Division. Absolute and relative morbidity burdens attributable to various illnesses and injuries among active component members of the U.S. Armed Forces, 2024. MSMR. 2025;32(9):4-12. Accessed May 13, 2026. https://health.mil/reference-center/reports/2025/09/01/msmr-vol-32-no-9-sep-2025
Armed Forces Health Surveillance Division. Ambulatory health care visits among active component members of the U.S. Armed Forces, 2024. MSMR. 2025;32(9):21-27. Accessed May 13, 2026. https://health.mil/reference-center/reports/2025/09/01/msmr-vol-32-no-9-sep-2025
Armed Forces Health Surveillance Division. Hospitalizations among active component members of the U.S. Armed Forces, 2024. MSMR. 2025;32(9):13-20. Accessed May 13, 2026. https://health.mil/reference-center/reports/2025/09/01/msmr-vol-32-no-9-sep-2025
Jones BH, Perrotta DM, Canham-Chervak ML, Nee MA, Brundage JF. Injuries in the military: a review and commentary focused on prevention. Am J Prev Med. 2000;18(3 suppl 1):71-84. doi:10.1016/s0749-379(99)00169-5
Lovalekar M, Hauret K, Roy T, et al. Musculoskeletal injuries in military personnel: descriptive epidemiology, risk factor identification, and prevention. J Sci Med Sport. 2021;24(10):963-969. doi:10.1016/j.jsams.2021.03.016

Hospitalizations among active component members of the U.S. Armed Forces, 2025

Wed, 01 Jul 2026 00:00:00 Z

What are the new findings?

In 2025, overall hospitalization rates for U.S. active component service members fell to a 10-year low of 49.2 per 1,000 person-years, driven by a pronounced decline in admissions to military hospitals and clinics. While mental health disorders remained the leading cause of hospitalization, this category experienced the largest absolute decline in admissions compared to 2023, whereas pregnancy and delivery saw the greatest absolute increase.

What is the impact on readiness and force health protection?

The persistent health care burden of mental health disorders and physical injuries, with prolonged hospital stays and high admission rates in specific service branches, affects force readiness directly by increasing lost duty time. These findings suggest that force health protection can be optimized through targeted, service-specific interventions designed to address the distinct occupational hazards and demographic differences identified throughout the Joint Force.

Background

This report documents the frequencies, rates, trends, and distributions of hospitalizations among active component service members (ACSMs) of the U.S. Army, Navy, Air Force, Space Force, and Marine Corps during calendar year 2025. Summaries are based on standardized hospitalization records at U.S. military and non-military (reimbursed through the Military Health System) medical facilities worldwide that are routinely maintained in the Defense Medical Surveillance System (DMSS).

In this report, primary (i.e., first-listed) discharge diagnoses are considered indicative of the primary cause of hospitalization. As in prior MSMR reports, summaries are based on the first 3 digits of the International Classification of Diseases, 10th Revision (ICD-10) codes of the primary discharge diagnoses. Hospitalizations not routinely documented by standardized, automated records, e.g., during field training exercises or while shipboard, are not available in a centralized location for health surveillance purposes and are excluded from this report. Incidence rates were calculated per 1,000 person-years (p-yrs). Percent change in incidence was calculated using unrounded rates.

Frequencies, rates and trends

In 2025, 62,833 hospitalizations were recorded for ACSMs of the U.S. Army, Navy, Air Force, Space Force, and Marine Corps (Table 1); of these hospitalizations, 47.3% occurred in non-military facilities (data not shown).

Total crude hospitalization rates declined to a low of 49.2 per 1,000 p-yrs in 2025, from a high of 54.1 per 1,000 p-yrs in 2016 representing a decrease of 9.1% during the 10-year surveillance period. This decline was more pronounced in military hospitals, falling from 37.2 per 1,000 p-yrs in 2016 to 25.9 per 1,000 p-yrs in 2025, representing approximately a 30% reduction over the same period. Between 2016 and 2019 hospitalization rates were relatively stable, fluctuating within a narrow range, but in 2020 rates dropped more than 10%. In 2021, the total hospitalization rate for military and non-military facilities rebounded to 51.3 per 1,000 p-yrs, approaching pre-pandemic levels. Meanwhile, the rates of hospitalization in military facilities remained stable from 2020 to 2021, declining thereafter through 2025 (Figure 1).

Hospitalizations, by ICD-10 major diagnostic categories

In 2025, merely 4 ICD-10 major diagnostic categories accounted for almost three-quarters (71.7%) of all active component hospitalizations: mental health disorders (29.9%), pregnancy and delivery (25.8%), injury and poisoning (8.2%), and digestive system diseases (7.9%) (Table 1). Consistent with findings from 2021 and 2023, hospitalizations for mental health disorders in 2025 accounted for more than any other major diagnostic category.

The largest absolute reduction in hospitalizations occurred in the mental health disorders diagnostic category, with 1,013 fewer hospitalizations in 2025 compared to 2023, constituting a 5.1% decline (Table 1). Several other categories experienced declines during the same period, including injury and poisoning (-360 hospitalizations, -6.6%), musculoskeletal diseases (-304 hospitalizations, -8.4%), ‘other’ factors influencing health status and contact with health services (-176 hospitalizations, -15.1%), and COVID-19-related admissions (-25 hospitalizations, -30.9%).

The pregnancy and delivery diagnostic category represented the largest absolute increase when comparing 2023 to 2025, rising by 744 hospitalizations. The largest relative increases in hospitalizations were observed for infectious and parasitic diseases (+352 hospitalizations, +35.2%), nervous system and sensory organ diseases (+282 hospitalizations, +21.5%), respiratory system diseases (+239 hospitalizations, +17.1%), and skin and subcutaneous tissue diseases (+89 hospitalizations, +11.9%) diagnostic categories.

Hospitalizations, by sex

In 2025, the hospitalization rate—for all causes—among active component service women was more than 3 times that of service men (114.6 per 1,000 p-yrs vs. 34.5 per 1,000 p-yrs, respectively). Excluding pregnancy and delivery, the rate of hospitalizations among women (45.2 per 1,000 p-yrs) was 30.9% higher than among men (34.5 per 1,000 p-yrs) in 2025 (data not shown). This rate difference was primarily due to hospitalizations for mental health disorders (female:male rate difference [RD] 5.8 per 1,000 p-yrs) and genitourinary system diseases (RD 2.2 per 1,000 p-yrs) (data not shown).

Excluding pregnancy and delivery, total hospitalization rates for most major diagnostic categories were comparable between men and women (data not shown), but sex-specific rates varied when stratified by age (Figure 2). Rates among women in all age groups were consistently higher for digestive system diseases, genitourinary system diseases, nervous and sensory organ diseases, endocrine and nutritional diseases, and blood and immune diseases. As in prior years, the sex disparity was greatest for conditions in the genitourinary system category, with women admitted at rates 3–5 times those of men of all age groups. Similarly, hospitalizations rates for neoplasms, congenital abnormalities, and blood and immune diseases were more than twice as high among women compared to men. In contrast, rates among men were higher than those among women in all age groups for conditions in the respiratory system diseases category. Hospitalization rates for mental health disorders were markedly higher for women than men in the younger age groups (<20 and 20-29 years); the gap narrowed significantly with age, and rates became nearly identical for the 30-39-years age group, after which the male rate was slightly higher.

Hospitalization rates among both sexes generally increased with age for most diagnostic categories except mental health disorders, skin and subcutaneous tissue diseases, and COVID-19. Rates decreased for both sexes with increasing age for mental health disorders and were relatively stable among all age groups for infectious and parasitic disease, skin and subcutaneous tissue disease, and blood and immune disease categories.

Most frequent diagnoses

Mental health disorder diagnoses, collectively, accounted for about 40% of all hospitalizations among men and—excluding pregnancy and delivery—among women. The pregnancy and delivery category was the leading major diagnostic category for women, accounting for over three-fifths (60.5%) of all female hospitalizations (Table 3). Adjustment disorders were the leading discharge diagnosis for mental health disorders among both men (n=4,771) and women (n=1,549) (Tables 2, 3) in 2025, accounting for over 30% of total mental health disorder hospitalizations. Besides adjustment disorders, the ranking of other frequent mental health diagnoses varied by sex: For men, the next most common conditions were alcohol dependence, major depressive disorder (recurrent severe without psychotic features), alcohol abuse, and unspecified depression, while, in contrast major depressive disorder was the second most frequent condition for women, followed by post-traumatic stress disorder (PTSD), alcohol dependence, and unspecified depression.

Durations of hospitalizations

When graphically represented, hospitalization durations demonstrate a highly right-skewed (positive) distribution, with the lower limit equal to 1 day and a mode of 3 days. Because hospital stay duration is not normally distributed, the median duration with interquartile range (IQR) was chosen as the best measure of central tendency. The median (IQR) duration of hospital stays (for all causes) has remained generally stable, at 3 (2-5) days, but increased to 4 (2-6) days in 2023 and remained at that level through 2025 (Figure 3).

Median duration days of hospitalization varied substantially by major diagnostic category. The shortest durations of stays (median days, IQR) were observed for genitourinary system, musculoskeletal system, and digestive system hospitalizations (2 days, 2-4). The longest stays were for mental health disorders (6 days, 4-10) and ‘other’ (6 days, 3-16) hospitalizations. The remaining categories had a median of 3 (2-7) days.

Five percent of hospitalization stays exceeded 10 days for one half of ICD diagnostic categories: blood and immune disorders (11 days); infectious and parasitic diseases (13 days); circulatory system diseases (13 days); nervous system and sensory organ diseases (20 days); symptoms, signs and ill-defined conditions (23 days); neoplasms (24 days); injury and poisoning (26 days); mental health disorders (32 days); and ‘other’ (primarily orthopedic aftercare and rehabilitation following prior illness or injury accounted for a majority of these bed days; 46 days) (Figure 4).

Hospitalizations, by service

While pregnancy and delivery accounted for more hospitalizations than any other diagnostic category among active component members of the Air Force and Space Force, among ACSMs of the Army, Navy, and Marine Corps, mental health disorders were the leading cause of hospitalization (Table 4). Among all the services, the crude hospitalization rate for mental health disorders in 2025 was highest for Army ACSMs (16.3 per 1,000 p-yrs).

Injury was the third leading hospitalization category among Army and Marine Corps ACSMs, at 5.1 per 1,000 p-yrs and 4.6 per 1,000 p-yrs, respectively. Among Navy, Air Force, and Space Force ACSMs, the third highest rate of hospitalization was for the digestive system diseases category: 4.1, 3.3, and 4.2 per 1,000 p-yrs, respectively.

Discussion

The findings of this 2025 surveillance report document an overall decline in hospitalization rates among U.S. ACSMs over the past decade, driven largely by a 30% reduction in admissions to military facilities. Despite this general decline in overall rates, the burden of inpatient care remains heavily concentrated within a few major diagnostic categories, predominantly mental health disorders and pregnancy and delivery. While mental health-related hospitalizations experienced a modest absolute decline when compared to 2023, they continue to account for the largest proportion of admissions overall and constitute the leading cause of hospitalization for Army, Navy, and Marine Corps personnel. The prolonged durations of hospital stays associated with mental health conditions—frequently exceeding 10 days—evidences the substantial health care resources within the Military Health System required to manage conditions such as adjustment disorders, major depressive disorders, and alcohol dependence.

Significant demographic and service-specific variations also persist, most notably the markedly higher overall admission rates among service women (114.6 per 1,000 p-yrs) compared to service men (34.5 per 1,000 p-yrs). These data are consistent with national hospitalization rate trends published in 2022 for women and men ages 18-44 years (95 per 1,000 p-yrs and 37 per 1,000 p-yrs, respectively) in the general U.S. population.¹ Even when excluding pregnancy and delivery, female service members required hospitalization at higher rates than their male counterparts, largely driven by mental health and genitourinary conditions. Furthermore, variations in leading causes of hospitalization among the service branches—with injury ranking high in the Army and Marine Corps, and digestive issues more prominent in the Air Force, Space Force, and Navy—highlights the diverse occupational exposures and physical demands inherent to different service environments. Continued surveillance and targeted, service-specific preventive interventions remain essential to address these vulnerabilities, optimize force readiness, and effectively allocate specialized medical resources.

Certain limitations should be considered when interpreting these results. This summary is based on primary (first-listed) discharge diagnoses only, but in many hospitalized cases multiple conditions can be present; for example, joint pain (musculoskeletal disease category) may be co-listed with an injury (injury category). In such cases, only the first-listed discharge diagnosis would be accounted in this report, which could under-estimate hospitalization rates for common conditions by bifurcating them into 2 or more sub-categories.

Since 2022, DMSS data have been housed in and analyzed from the Military Health System Information Platform (MIP). All military treatment facilities are now using GENESIS software to electronically capture medical care. Data completeness issues related to data transfers from GENESIS to the Medical Data Store (MDR) to DMSS have improved significantly. Regardless of the electronic system used to capture hospitalizations, every hospitalization record requires completion of a discharge summary before the event record is reported in the system. The data presented in this report were extracted from DMSS on April 20, 2026. Consequently, timeliness of reporting can still be an issue that may lead to underestimates of true counts and rates of hospitalizations for the most recent year of reporting. As a result, direct comparison of data reported in the current report with prior year publications should be interpreted with caution.

Reference

National Center for Health Statistics, Centers for Disease Control and Prevention. Table: people with hospital stays in the past year, by selected characteristics—United States, selected years 1997–2019. National Hospital Care Survey. U.S. Dept. of Health and Human Services. Accessed May 26, 2026. https://www.cdc.gov/nchs/data/hus/2020-2021/hospstay.pdf

Medical evacuations among active and reserve component members of the U.S. Armed Forces, 2025

Wed, 01 Jul 2026 00:00:00 Z

What are the new findings?

From 2021 to 2025, disease and non-battle injuries, rather than combat trauma, led to nearly all medical evacuations within 4 U.S. combatant commands: U.S. Africa Command (AFRICOM), U.S. Central Command (CENTCOM), U.S. Pacific Command (PACOM), and U.S. Southern Command (SOUTHCOM). In 2025 CENTCOM and PACOM had the highest volumes of medical evacuations, with mental health disorders the leading cause in both theaters of operations.

What is the impact on readiness and force health protection?

Optimization of operational readiness and the minimization of preventable lost duty time each requires the prioritization of robust, in-theater mental health assets and targeted musculoskeletal injury prevention programs. In addition, the adaptation of force health protection strategies to the unique logistical and demographic challenges of each combatant command remains essential.

Background

This report summarizes the nature, numbers, and trends of conditions for medical evacuations of U.S. service members in 2025 from U.S. areas of responsibility (AORs) U.S. Africa Command (AFRICOM), U.S. Central Command (CENTCOM), U.S. Pacific Command (PACOM, formerly U.S. Indo-Pacific Command or INDOPACOM), and U.S. Southern Command (SOUTHCOM), with historical comparisons to the prior 4 years. During deployment operations, initial medical care is provided by military medical personnel in the operational theater, but some injuries and illnesses require treatment outside the theater of operation. Individuals may be transported to a permanent military medical facility, usually in Europe or the U.S., for definitive diagnosis or care. Because medical evacuations are resource-intensive, they are initiated for serious conditions, some directly related to participation in, or support of, military operations. Conditions unrelated to operational activities but which necessitate medical evacuation may be preventable.

To accurately reflect the geographic distribution of U.S. force deployment, medical evacuation surveillance has expanded. In 2021 AFRICOM was first included in this report; after the reduction of large-scale U.S. combat operations in CENTCOM in late 2021, global distribution of U.S. military operations shifted significantly, but to sustain counterterrorism successes, force deployments continue to assist, advise, and accompany allied security forces.¹ In accordance with the National Defense Strategy’s focus on global strategic competition, operational tempos remain high, with U.S. forces increasingly dispersed in multiple theaters to deter aggression and build regional alliances.² Consequently, this year’s report includes 4 geographic combatant commands.

Methods

The surveillance population for this analysis includes all members of the active and reserve components of the U.S. Army, Navy, Air Force, Marine Corps, and Space Force deployed to AFRICOM, CENTCOM, PACOM, or SOUTHCOM for any duration from January 1, 2021 through December 31, 2025. Medical evacuations by the U.S. Transportation Command (TRANSCOM) were assessed in records maintained in the TRANSCOM Regulating and Command & Control Evacuation System (TRAC2ES). Combatant command evacuation data are presented separately.

Specific constraints were applied to AOR origin and destination pairings. For movements originating in AFRICOM, CENTCOM, and SOUTHCOM, the destination theater had to be distinct from the origin theater, to filter for inter-theater transportation. Conversely, a destination restriction was omitted for movements originating in PACOM; given the vast geographic distribution and operational necessity of intra-theater transportation within PACOM, evacuation destinations within the same theater of origin were permitted for that AOR.

Medical evacuations were classified by cause and nature of the precipitating medical condition, based on relevant evacuation and medical records. All medical evacuations were classified as battle- or non-battle injuries and illnesses, based on TRAC2ES evacuation record entries. Evacuations due to non-battle injuries and illnesses were further classified into 18 illness and injury categories based on International Classification of Diseases, 9th and 10th revisions (ICD-9 and ICD-10, respectively) diagnostic codes reported in medical records following evacuation.

All records of hospitalizations and ambulatory visits at a military medical facility in the U.S. or Europe, within 5 days preceding to 10 days following the reported date of each medical evacuation, were identified from Defense Medical Surveillance System (DMSS) data. The primary (i.e., first-listed) diagnosis for either hospitalization or earliest ambulatory visit after evacuation was used to classify the condition that necessitated evacuation. If the first-listed diagnostic code specified an external cause of injury (ICD-9 ‘E’ code, ICD-10 ‘V’, ‘W’, ‘X’, ‘Y’ codes) or an encounter for a condition other than a current illness or injury, the secondary diagnosis code (ICD-9, 001–999; ICD-10, A00–T88, U07.1, U09.9) was used. If no secondary diagnosis was provided, or if the secondary diagnosis also was an external cause code, the first-listed code of a subsequent encounter was used.

Results

In 2025, the U.S. Armed Forces recorded a total of 1,107 medical evacuations in the 4 combatant commands, with the majority originating from CENTCOM (n=609) and PACOM (n=336). AFRICOM and SOUTHCOM accounted for substantially lower operational volumes in 2025, reporting 142 and 20 evacuations, respectively. Service men comprised most evacuated personnel, reflecting the broader demographic composition of deployed forces, although proportional trends within specific diagnostic categories varied by sex.

Only 5 battle injuries were recorded in total, in all 4 AORs—with all 5 originating in CENTCOM—representing less than 1% of specific in-theater evacuations (Table 1). Mental health disorders constituted the leading cause of evacuation in PACOM (39.9% of total) and CENTCOM (29.9%). Conversely, non-battle injuries and poisonings were the leading cause for evacuations out of SOUTHCOM (40.0%) and AFRICOM (21.8%), which also represented the secondary cause of evacuations from CENTCOM (25.1%). In PACOM, diagnoses related to the musculoskeletal system accounted for the secondary cause (21.1%) of medical evacuation.

CENTCOM evacuations for disease and non-battle injury (DNBI) peaked in the third quarter of 2021, with 297 evacuations, before declining to 148 quarterly evacuations at the end of 2025 (Figure). Evacuations due to DNBI from PACOM peaked in the first quarter of 2022, at 190 evacuations, thereafter declining to 64 evacuations in the final quarter of 2025. Annual medical evacuations from AFRICOM exceeded 200 during the first 3 years of the surveillance period but in 2025 declined to less than 150. During the entire surveillance period, total quarterly numbers of SOUTHCOM medical evacuations rarely exceeded double digits.

Demographic and military characteristics

Evacuees were predominantly male (75-84%), ages 20-29 years, and typically among the enlisted ranks (Table 2). The Army accounted for the most medical evacuations, by branch of service, in every region except SOUTHCOM, where Navy personnel represented 40% of all medical evacuations. A notable regional difference emerged by component stratification: While active duty service members accounted for most evacuations in CENTCOM, PACOM, and SOUTHCOM, Guard and reserve personnel made up nearly 70% of AFRICOM evacuations.

Service members in communications and intelligence as well as repair and engineering occupations experienced the highest numbers of medical evacuations. While most evacuations in AFRICOM, CENTCOM, and PACOM (77-88%) were classified as “Routine” and primarily involved military transportation, SOUTHCOM handled a distinctly higher proportion of “Priority” (35%) and “Urgent” (30%) evacuations that largely relied on non-military or unknown transportation modes.

Most frequent specific diagnoses

In CENTCOM, stress and adjustment disorders were the most frequent diagnoses by a wide margin, accounting for 102 male and 35 female evacuations (Table 3). This diagnosis similarly led AFRICOM’s list for both sexes, followed closely by “administrative examinations and lower-extremity injuries.” In PACOM, the most frequent diagnostic codes demonstrated slight differences by sex. Alcohol-related disorders led among service men, with 32 evacuations, while joint disorders represented the top diagnosis (n=17) for evacuations of service women. In all combatant commands, musculoskeletal ailments, such as joint disorders, dorsalgia and back pain, and knee injuries, consistently ranked as the most common physical causes of medical evacuation.

Discussion

This surveillance report reveals that disease and non-battle injuries, rather than combat trauma, accounted for nearly all 2021–2025 medical evacuations from AFRICOM, CENTCOM, PACOM, and SOUTHCOM AORs. With battle injuries accounting for less than 1% of total evacuations, these data emphasize the continued need for focused force health protection efforts on prevention and treatment of mental health and musculoskeletal conditions. While the general decline in quarterly evacuation volumes in CENTCOM and PACOM, following peaks in 2021 and 2022, likely reflects broader shifts in force posture, the persistent average numbers of DNBI evacuations evidences the continuous physical and psychological demands on deployed service members.

These distinct regional and demographic profiles reported suggest that mission-specific operational tempos and environments significantly influence medical readiness. The predominance of mental health conditions—specifically, stress, adjustment, and alcohol-related disorders—as leading causes for evacuation in CENTCOM and PACOM reveals a critical need for robust, in-theater psychological support. Notably, the proportions of medical evacuations due to mental health disorders are now considerably higher than the proportion (11.6%) described by a MSMR report of evacuations from Iraq during a 9-year period, 2003-2011.³ Furthermore, theater-specific distinctions highlight unique logistical and personnel challenges, such as AFRICOM’s heavy reliance on National Guard and reserve personnel and SOUTHCOM’s elevated rate of urgent, high-priority evacuations requiring non-military transportation.

The concentration of evacuations among communications and intelligence as well as repair and engineering personnel suggests that these essential support roles may involve substantial, perhaps under-recognized, occupational health risks; the data are not presented in proportion to the populations at risk, however, so these results should be interpreted with caution. Demographic data for the deployed population, i.e., person-time for individuals eligible for medical evacuation, are not readily available. The lack of deployed individual person-time data precludes calculation of stratified and overall rates for medical evacuations.

Additional limitations should be considered when interpreting these results. Most causes of medical evacuations were estimated for this report from primary (i.e., first-listed) diagnoses in DMSS recorded during hospitalizations or initial outpatient encounters following evacuation, based on DMSS data extracted on May 26, 2026. Diagnoses recorded in-theater through the Theater Medical Data Store (TMDS) are not represented in this analysis. In some cases, clinical evaluations at permanent treatment facilities following evacuation may have eliminated serious conditions that were clinically suspected while in theater, resulting in possible misclassification errors. When interpreting these evacuation metrics, methodological inclusion of intra-theater movements within PACOM should also be considered. While PACOM intra-theater inclusion reflects the vast geography and operational realities of the Indo-Pacific region, it distinguishes PACOM’s data from the inter-theater evacuations recorded for the other combatant commands. Finally, battle injuries rely on proper classification in TRAC2ES, but misclassification errors may occur. Due to the small number of battle injuries, any misclassification will have a disproportionate effect.

References

The White House. Letter to the Speaker of the House and President pro tempore of the Senate Regarding the War Powers Report. Dec. 6, 2024. Accessed Apr. 18, 2025. https://bidenwhitehouse.archives.gov/briefing-room/statements-releases/2024/12/06/letter-to-the-speaker-of-the-house-and-president-pro-tempore-of-the-senate-regarding-the-war-powers-report-5
U.S. Department of Defense. 2022 National Defense Strategy of the United States of America. U.S. Dept. of Defense;2022. Accessed Jun. 16, 2026. https://media.defense.gov/2022/oct/27/2003103845/-1/-1/1/2022-national-defense-strategy-npr-mdr.pdf
Armed Forces Health Surveillance Center. Medical evacuations from Operation Iraqi Freedom/Operation New Dawn, active and reserve components, U.S. Armed Forces, 2003–2011. MSMR. 2012;19(2):18-21. Accessed Jun. 16, 2026. https://health.mil/reference-center/reports/2012/01/01/medical-surveillance-monthly-report-volume-19-number-2

Absolute and relative morbidity burdens attributable to various illnesses and injuries among non-service member beneficiaries of the Military Health System, 2025

Wed, 01 Jul 2026 00:00:00 Z

What are the new findings?

Analysis of 2025 data reveals that non-service member beneficiaries of the Military Health System remain overwhelmingly reliant upon outsourced care: Roughly 70% of TRICARE-eligible and more than 91% of Medicare-eligible individuals received their health care exclusively from civilian providers. The 2025 data also reveal distinct, age-related burdens of morbidity. While both mental health and developmental disorders dominate provision of care for beneficiaries under age 45 years, musculoskeletal system and cardiovascular conditions constitute the primary health care encounters for older adults.

What is the impact on readiness and force health protection?

The 2024-2029 Military Health System (MHS) Strategy aims to attract as well as re-attract beneficiaries to MHS medical facilities, not only to improve System efficiency but to purposely fulfill the nation’s promise to care for its military beneficiaries, as well as enriching the clinical experience for the ready military medical force. Continued evaluation of health care provision and diagnostic patterns may aid senior leaders’ resource allocation to realize current MHS strategy and goals.

Background

Operating as a globally integrated health delivery network, the Military Health System (MHS) executes a dual mandate: ensuring the operational medical readiness of the U.S. Armed Forces and providing comprehensive health care to eligible personnel and their dependents.¹ This system relies on a hybrid model, balancing care delivered at military hospitals and clinics, known as the direct care system, with civilian care facilitated by the TRICARE network. Fulfilling its commitment to service members, retirees, and their families, the MHS provided TRICARE eligibility to approximately 9.4 million beneficiaries in fiscal year 2024.²

Due to the diversity of this beneficiary population, health care enrollment and provision patterns vary significantly among different demographic categories.² To optimize this complex network, the current Department of War (DOW) strategy, guided by the MHS Strategy for Fiscal Years 2024-2029 and recent stabilization directives, heavily prioritizes rebuilding direct care capacity.³ A central objective of this strategy is to “attract and reattract beneficiaries to military treatment facilities,” a shift designed to maximize system efficiency, enrich clinical case diversity, and sustain the medical proficiency of the Ready Medical Force.^4,5

When interpreting these usage patterns, the structural transition of health benefits at age 65 years is a critical factor. For beneficiaries younger than age 65 years, care is distributed between military hospitals and clinics and civilian providers. Upon reaching age 65 years and gaining Medicare eligibility, standard TRICARE coverage converts to TRICARE for Life (TFL), a Medicare supplement funded independently of the Defense Health Program. While Medicare-eligible individuals can still access military hospitals and clinics, depending on space availability, their care is predominantly outsourced via the civilian health care system. Consequently, morbidity burdens must be analyzed within specific age cohorts and care settings to accurately reflect their true impacts on MHS resources.

Building on prior annual analyses, this report quantifies the health care burdens of non-service member MHS beneficiaries during calendar year 2025. Morbidity was assessed using a modified Global Burden of Disease (GBD) classification framework^6-9 in conjunction with standard International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) diagnostic groupings for both hospitalizations, or inpatient visits, and ambulatory care, or outpatient visits. To account for the distinct health care provision differences driven by the TRICARE-to-Medicare transition, the resulting estimates are stratified by 4 age categories, with beneficiaries ages 65 years and older analyzed separately.

Methods

The surveillance population included all non-service member MHS beneficiaries who had at least 1 hospitalization or outpatient medical encounter from January 1 through December 31, 2025, with either a military hospital, clinic, or health care provider, or through a civilian facility or provider (if reimbursed through TRICARE or through Medicare with a co-payment by TFL). All inpatient and outpatient medical encounters for this analysis were summarized according to the primary (i.e., first-listed) ICD-10-CM codes that indicate the natures of illnesses or injuries (A00–T88). Nearly all records of encounters with first-listed diagnoses coded with ‘Z’ (“care other than for a current illness or injury,” e.g., general medical examinations, after care, vaccinations) or ‘V’, ‘W’, ‘X’, or ‘Y’ (“indicators of the external causes but not the natures of injuries”) were excluded from the analysis; encounters with a code of Z37 (“outcome of delivery”) in the primary position were retained.

For summary purposes, all illness- and injury-specific diagnoses (as defined by ICD-10) were grouped into 157 burden of disease-related conditions and 25 major morbidity categories, based upon a modified version of the classification system developed for the GBD Study. The methodology for summarizing absolute and relative morbidity has been used annually since 2014 and is described elsewhere.⁸ Results were stratified by source of health care (direct care [i.e., military hospitals and clinics] vs. civilian facilities) and by age group (0-17 years, 18-44 years, 45-64 years, 65 years and older). For analysis of morbidity burdens within the youngest age group, developmental disorders were included in the general category of mental health disorders.

Results

In 2025, the population of non-service member MHS care recipients included more female (57.3%) than male (42.7%) beneficiaries. Adults ages 65 years or older accounted for the highest number of individuals receiving health care (n=2.06 million, 33.5%), followed by pediatric beneficiaries ages 0-17 years (n=1.44 million, 23.3%), adults ages 18-44 years (n=1.37 million, 22.1%), and older adults ages 45-64 years (n=1.30 million, 21.1%) (Table 1).

In 2025, a total of 6,166,782 non-service member MHS beneficiaries had 93,079,550 recorded medical encounters. Over half (52.9%) of those medical encounters were among 2,063,683 MHS beneficiaries ages 65 years and older (Table 1). Provision of care for the oldest age group was almost exclusively from civilian providers, with 91.2% of individuals ages 65 years or older having medical encounters or hospital bed days documented only from reimbursements processed for care at civilian facilities (Table 2). Among TRICARE-eligible beneficiaries (younger than age 65 years), health care was also almost exclusively from civilian facilities. Adults ages 18-44 years received approximately one-third of their care exclusively from military hospitals and clinics (11.4%) or a combination of direct and outsourced care (19.4%) (Table 2).

The 3 most frequent morbidity-related categories accounting for the most medical encounters among TRICARE-eligible beneficiaries included mental health disorders, injuries, and symptoms, signs and ill-defined conditions (Figure 1a). Mental health disorders also represented the leading category for hospital bed days for beneficiaries younger than age 65 years, followed by maternal conditions (Figure 1b).

Pediatric beneficiaries younger than age 18 years

Pediatric patients accounted for 14.4% of all medical encounters, 23.3% of all individuals affected, and 9.6% of all hospital bed days among non-service member MHS beneficiaries in 2025 (Table 1). On average, each pediatric beneficiary experienced 9.3 medical encounters during the year. Provision of care for pediatric patients was primarily through reimbursement for care in civilian facilities (70.4%), followed by a combination of direct and outsourced care (18.8%). Only 10.8% of pediatric patients received all medical encounters or hospital bed days directly from MHS providers (Table 2).

In 2025, mental health disorders represented the largest burden of disease among pediatric beneficiary medical encounters (40.2%, n=5,374,051) and contributed to the greatest number of hospital bed days (58.3%, n=334,980) (Figures 2a, 2b). On average, pediatric beneficiaries affected by a mental health disorder had 16.2 medical encounters during the year specifically related to this morbidity category (data not shown). More than two-thirds (70.3%) of all medical encounters for mental health disorders among pediatric beneficiaries were attributed to 3 groups of disorders: autistic disorders and pervasive developmental disorders (35.4%), developmental disorders of speech and language (23.6%), and attention-deficit hyperactivity disorders (11.4%) (Figure 2c). Pediatric patients affected by an autistic disorder had, on average, 41.4 autism-related encounters per individual (data not shown).

Over two-thirds (64.5%) of hospital bed days related to mental health disorders among pediatric beneficiaries were attributable to mood disorders. Among all mood disorder-related hospital bed days, over 60% were attributed to 2 diagnostic categories: recurrent severe major depressive disorder without psychotic features (30.8%, ICD-10 F332) and disruptive mood dysregulation disorder (31.7%, ICD-10 F3481) (data not shown).

Perinatal conditions, or medical issues occurring within 1 year of birth, accounted for the second highest number of hospital bed days (n=47,254, 8.2%) in 2025 among pediatric beneficiaries, after mental health disorders (Figures 2a, 2b). Pediatric beneficiaries affected by malignant neoplasms had, on average, 13.5 neoplasm-related encounters per individual. The highest numbers of malignant neoplasm-related encounters and hospital bed days were attributable to leukemias (data not shown).

Respiratory infections (including upper and lower respiratory infections and otitis media) accounted for more medical encounters (8.9%) among pediatric beneficiaries compared to any older age group of beneficiaries (Figures 2b, 3b, 4b, 5b).

Beneficiaries ages 18–44 years

Individuals ages 18-44 years accounted for 14.4% of all medical encounters, 22.1% of all individuals affected, and 10.6% of hospital bed days among non-service member MHS beneficiaries in 2025 (Table 1). On average, each individual ages 18-44 years affected with an illness or injury (of any cause) had 9.8 medical encounters during the year. Provision of care for beneficiaries ages 18-44 years was primarily (69.2%) through reimbursement for care in civilian facilities, followed by a combination of direct and outsourced care (19.4%). Only 11.4% of beneficiaries ages 18-44 years received all medical encounters or hospital bed days directly from MHS providers (Table 2).

Mental health disorders accounted for the most medical encounters (n=3,444,190, 25.6%) among adult MHS beneficiaries ages 18-44 years in 2025 (Figures 3a, 3b), also representing about one-fifth (19.9%) of total hospital bed days, and on average, 8.8 mental health-related encounters per individual. Anxiety disorders (37.1%), mood disorders (28.9%), and adjustment disorders (14.2%) accounted for over three-quarters (80.2%) of all medical mental health care encounters (data not shown). Mood and substance abuse disorders accounted for over three-quarters (48.6% and 26.7%, respectively) of hospital bed days required for mental health disorders.

Maternal conditions accounted for more than two-fifths (n=282,691, 44.5%) of all hospital bed days among adults ages 18-44 years, as well as, on average, 6.7 medical encounters per affected individual (Figures 3a, 3b). Of the 282,691 hospital bed days for maternal conditions, 64.0% were attributed to pregnancy complications, with 18.9% due to infant deliveries (data not shown).

Malignant neoplasms, as a diagnostic group, resulted in 7.0 encounters, on average, per individual in 2025. Of the 106,604 medical encounters for malignant neoplasms among adults ages 18-44 years, 32.9% were attributed to malignant neoplasm of the breast (data not shown).

Beneficiaries ages 45–64 years

Non-service member beneficiaries ages 45-64 years constituted approximately one-fifth (18.3%) of all medical encounters, 21.1% of all individuals affected, and 12.6% of hospital bed days in 2025 (Table 1). Each affected individual ages 45-64 years had, on average, 13.1 medical encounters during the year. Provision of care for beneficiaries ages 45-64 years was primarily (73.5%) through reimbursement for care in civilian facilities, followed by a combination of direct and outsourced care (19.0%). Only 7.5% of beneficiaries ages 45-64 years received all medical encounters or hospital bed days directly from MHS providers (Table 2).

Of all morbidity-related categories, musculoskeletal diseases accounted for the most medical encounters (n=2,409,259, 14.2%) among older adult beneficiaries ages 45-64 years (Figures 4a, 4b); back problems accounted for 41.7% of those musculoskeletal disease-related encounters (data not shown). Injuries represented the highest proportion of hospital bed days (16.9%) among adults ages 45-64 years, followed by cardiovascular diseases (16.0%). Digestive diseases (9.4%) and malignant neoplasms (8.1%) accounted for larger percentages of total hospital bed days among beneficiaries of this age group compared to other age groups.

Malignant neoplasm of the breast represented the leading cause of neoplasm-related encounters (26.3%) in adult beneficiaries ages 45-64 years (data not shown).

Medicare-eligible beneficiaries, ages 65 years and older

In 2025, non-service member beneficiaries ages 65 years or older accounted for the largest proportion (52.9%) of medical encounters, and their hospital bed days were more than double all other age groups combined. On average, each affected individual in Medicare-eligible age group had 23.9 medical encounters during the year (Table 1). Provision of care for Medicare-eligible beneficiaries was primarily through reimbursement of care from civilian facilities (91.2%); only 2% received all medical encounters or hospital bed days directly from MHS providers (Table 2).

Musculoskeletal diseases (n=7,371,419, 15.0%) and cardiovascular diseases (n=6,846,617, 13.9%) together represented the leading causes for medical encounters among beneficiaries ages 65 years or older, while injury (n=875,871, 21.7%) and cardiovascular diseases (816,180 days, 20.2%) were the leading diagnostic categories for their hospital bed days (Figures 5a, 5b). Back problems accounted for a little more than one-third (35.0%) of all musculoskeletal disease-related medical encounters among individuals ages 65 years and older (data not shown).

Discussion

These findings from calendar year 2025 reveal a continued reliance on civilian care among all age groups of non-service member MHS beneficiaries. To improve access and sustain clinical readiness, DOW’s strategy for fiscal years 2024-2029 prioritizes “attracting and reattracting” beneficiaries to military hospitals and clinics. These data, however, demonstrate that most care is still nearly exclusively civilian for TRICARE-eligible beneficiaries (younger than age 65 years): 70.4% for those ages 0-17 years, 69.2% for those ages 18-44 years, and 73.5% for those ages 45-64 years.

Notably, MHS beneficiaries receive higher health care provision compared to the general U.S. population. Compared to the National Ambulatory Medical Care Survey of 2019, which documented 3.2 ambulatory visits per person-year among the civilian population, non-service member MHS beneficiaries had 14.6 ambulatory health care visits per person-year.¹⁰ Since the National Ambulatory Medical Care survey includes uninsured individuals, financial barriers to care may explain a portion of the lower overall use rate among the general U.S. population. Conversely, MHS beneficiaries benefit from comprehensive coverage with minimal direct payment, or out-of-pocket costs, which drives higher general provision of care, while the unique stressors of military life may also generate significant demand for specific services, particularly mental health care.^11,12

Consistent with prior years, this analysis reveals age-related contrasts in morbidity burdens. For pediatric (ages 0-17 years) and younger adult (ages 18-44 years) populations, mental health disorders remain the overwhelming cause of health care. In pediatric patients, outpatient mental health services are primarily influenced by developmental disorders, with nearly 70% of mental health encounters attributable to autistic disorders, developmental speech and language disorders, or attention-deficit hyperactivity disorders. Similarly, young adults seek extensive outpatient care for anxiety and mood disorders, while maternal conditions continue to account for the highest proportion of hospital bed days for the ages 18-44 years group.

In older MHS beneficiaries, the burden of health care shifts to chronic physical conditions and injuries, continuing trends consistent with 2024 data.¹⁴ Individuals ages 45 or older account for the highest volume of medical encounters, predominantly due to musculoskeletal conditions. Furthermore, injuries and cardiovascular diseases constitute the leading causes of hospital bed days for both the ages 45-64 years and Medicare-eligible (ages 65+ years) populations. Because the Medicare-eligible demographic generates the highest care provision rates but relies almost exclusively on non-MHS resources via Medicare and TFL, their direct impact on military hospital capacity remains mitigated.

While this report provides a comprehensive overview of morbidity-related diagnoses, it is inherently limited to care billed through TRICARE or Medicare (with TFL). Care paid for directly, or out-of-pocket, or through other unbilled primary health insurance, is not captured. This summary is based on primary (i.e., first-listed) diagnosis codes reported on ambulatory visit records and discharge diagnoses for hospitalizations; this summary discounts morbidity related to co-morbid and complicating conditions that may have been documented in secondary diagnostic positions. The accuracy of reported diagnoses likely varies according to medical condition, clinical setting, care provider, and health care facility, as the data were collected for non-surveillance purposes. The data presented in this report were extracted from DMSS on May 1, 2026.

Continued evaluation of health care provision and diagnostic patterns may aid senior leaders’ allocation of resources for realization of the current MHS strategy and goals. The gap between the reliance on civilian care and the strategic vision for the MHS is actively being addressed at the highest levels of the DOW. Ultimately, reversing the trend of outsourced care is not merely an administrative goal but strategic imperative: As noted by Defense Health leadership, providing accessible, high-quality care within the MHS directly sustains medical proficiency, ensuring that when military medical personnel take care of beneficiaries, they inherently increase the readiness of the total force.¹⁵

References

Mendez BHP, Congressional Research Service. Defense Primer: Military Health System. In Focus (10530). Library of Congress. Updated Oct. 2024. Accessed Aug. 5, 2025. https://www.congress.gov/crs-product/if10530
Chief Data and Analytics Office, Defense Health Agency. Fiscal Year 2024 TRICARE Program Evaluation Report. U.S. Dept. of War. Sep. 23, 2025. Accessed May 15, 2026. https://www.health.mil/reference-center/reports/2025/09/23/annual-evaluation-of-the-tricare-program-fy24
Military Health System. Military Health System Strategy: Fiscal Years 2024-2029. Defense Health Agency, U.S. Dept. of War. Accessed Aug. 5, 2025. https://health.mil/reference-center/publications/2023/12/15/mhs_strategic_plan_fy24_29
Office of the Deputy Secretary of Defense. Memorandum: Stabilizing and Improving the Military Health System. U.S. Dept. of War. Dec. 6, 2023.
Office of the Under Secretary of Defense. Memorandum for Senior Pentagon Leadership, Defense Health Agency and DoD Field Activity Directors: Directive-Type Memorandum 24-003–“Military Health System Manpower Requirements Determination, Resourcing, and Assignment”. U.S. Department of War. Jun. 2024. Accessed Jun. 26, 2026. www.esd.whs.mil/portals/54/documents/dd/issuances/dtm/dtm-24-003.pdf?ver=nzqjvmhrb8dohutj8wgqa%3d%3d
Murray CJ, Lopez AD, Jamison DT. The global burden of disease in 1990: summary results, sensitivity analysis and future directions. Bull World Health Organ. 1994;72(3):495-509. Accessed Aug. 26, 2025. https://iris.who.int/bitstream/handle/10665/41177/9241561750_en_part2.pdf;jsessionid=3145C7676FA5B9E812A71046BA6326A2?sequence=2
World Health Organization. The Global Burden of Disease: 2004 Update. World Health Organization;2008. Accessed Aug. 26, 2025. https://www.who.int/publications/i/item/9789241563710
Murray CJL. The Global Burden of Disease Study at 30 years. Nat Med. 2022;28(10):2019-2026. doi:10.1038/s41591-022-01990-1
Roser M, Ritchie H, Spooner F. Burden of disease. Our World in Data. Updated Feb. 2024. Accessed May 2, 2024. https://ourworldindata.org/burden-of-disease
Murray CJL, Lopez AD, eds. The Global Burden of Disease: A Comprehensive Assessment of Mortality and Disability from Diseases, Injuries, and Risk Factors in 1990 and Projected to 2020. Harvard University Press;1996:120-122.
Santo L, Kang K., National Center for Health Statistics. National Ambulatory Health Care Survey: 2019 National Summary. Centers for Disease Control and Prevention, U.S. Dept. of Health and Human Services. 2019. Accessed May 24, 2024. https://www.cdc.gov/nchs/data/ahcd/namcs_summary/2019-namcs-web-tables-508.pdf
Frakes MD, Gruber J, Justicz T. Public and private options in practice: the Military Health System. Am Econ J Econ Policy. 2023;15(4):37-74. doi:10.1257/pol.20210625
Wooten NR, Brittingham JA, Pitner RO, et al. Purchased behavioral health care received by Military Health System beneficiaries in civilian medical facilities, 2000–2014. Mil Med. 2018;183(7-8):e278-e290. doi:10.1093/milmed/usx101
Armed Forces Health Surveillance Division. Absolute and relative morbidity burdens attributable to various illnesses and injuries among non-service member beneficiaries of the Military Health System, 2024. MSMR. 2024; 32(9):45-54. Accessed Jun. 12, 2026. https://www.health.mil/news/articles/2024/07/01/msmr-mhs-beneficiaries-2023
Mincher R, Military Health Systems Communications. Military Health System Stabilization: Rebuilding Health Care Access Is Critical to Patient’s Well-Being. U.S. Dept. of War. 2024. Accessed Jun. 10, 2026. https://www.defense.gov/news/news-stories/article/article/3652092/military-health-system-stabilization-rebuilding-health-care-access-is-critical

Surveillance snapshot: Illness and injury burdens among recruit trainees of the active component of the U.S. Armed Forces, 2025

Wed, 01 Jul 2026 00:00:00 Z

Surveillance snapshot: Illness and injury burdens among reserve component members of the U.S. Armed Forces, 2025

Wed, 01 Jul 2026 00:00:00 Z

Surveillance snapshot: Telehealth services among active component members of the U.S. Armed Forces, 2021–2025

Wed, 01 Jul 2026 00:00:00 Z

Telehealth in the Military Health System (MHS) has long been an important tool for providing care in deployed and non-deployed settings.¹ The U.S. Department of War uses telehealth for primary care, medication management,² and other services including outpatient care. Certain types of care provided at fixed military hospitals and clinics, as well as health care encounters outside the military medical system that are billed to TRICARE, are also provided through telehealth.³

This Surveillance Snapshot presents trends in telehealth service use and identifies the 10 most frequent diagnoses addressed via telehealth among U.S. active component service members (ACSMs) using Defense Medical Surveillance System (DMSS) outpatient and demographic records from January 2021 through December 2025. Telehealth services were identified by a virtual appointment type through video visit or My Military Health Virtual (MMH VIDEO) or by Common Procedural Terminology (CPT) codes 98966–98969, 99374–99380, 99339–99444, 99421–99423, 98000–98007, G0320–G0321, G0425–G0427, G0459, G0508–G0509, D9995, G2061–G2063, C7900–C7902, and T1014.

Use of telehealth was defined as having at least 1 telehealth encounter per patient per day; if a patient had multiple telehealth encounters per day, the first record was retained as the qualifying encounter. Reasons for telehealth encounters among ACSMs were determined using International Classification of Diseases, 10th Revision codes associated with each telehealth visit. The rate of telehealth encounters was calculated per 10,000 encounter records and stratified by year, patient demographics, and type of care (military hospitals or clinics or civilian care). Because the underlying database is static yet constantly updated, the quantitative figures presented in this report differ slightly from data reported for the same periods in prior analyses.

A total of 3,694,460 telehealth encounters were provided to over 1,147,951 ACSMs during the 5-year period. The overall unadjusted rate of telehealth per 10,000 encounters evinces an upward trajectory from 2021 through 2025, rising from 242.3 to 633.4 per 10,000 encounters (Table). Over the 5-year period, women used telehealth at a higher overall rate than men (419.4 and 396.6 per 10,000 encounters, respectively), although this trend inverted in 2024 and 2025, with men availing telehealth services at higher rates.

The leading 10 reasons for telehealth encounters from 2021 through 2025 were other general symptoms and signs, obstructive sleep apnea, encounter for other administrative examinations, occupational Health Periodic Health Assessment examination, encounter for immunization, low back pain, pain in right knee, pain in left knee, adjustment disorder with mixed anxiety and depressed mood, and pain in right shoulder (data not shown).

The highest rates were observed in 2025 among male service members (641.2 per 10,000 encounters), those ages 30-34 years (678.6 per 10,000 encounters), Space Force ACSMs (1,227.2 per 10,000 encounters), individuals treated by a military hospital or clinic (953.2 per 10,000 encounters), and ACSMs of other races and ethnicities (682.0 per 10,000 encounters) (Table).

The steady increase of telehealth encounter rates from 2021 through 2025 indicates a growing role for virtual care among ACSMs.

References

Madsen C, Banaag A, Koehlmoos TP. Analysis of telehealth usage and trends in the Military Health System, 2006-2018. Telemed J E Health. 2021;27(12):1346-1354. doi:10.1089/tmj.2020.0474
Vaudreuil R, Langston DG, Magee WL, et al. Implementing music therapy through telehealth: considerations for military populations. Disabil Rehabil Assist Technol. 2022;17(2):201-210. doi:10.1080/17483107.2020.1775312
Gilder T, Banaag A, Madsen C, Koehlmoos TP. Trends in telehealth care during the COVID-19 pandemic for the Military Health System. Telemed Rep. 2023;4(1):147-155. doi:10.1089/tmr.2022.0042

Authors’ Affiliation

Epidemiology and Analysis Branch, Armed Forces Health Surveillance Division, Public Health Directorate, Defense Health Agency, Silver Spring, MD: Mr. Adegboye, Dr. Mabila

Military medicine is a ‘no-fail mission’ says Department of War top military health leader

Wed, 27 May 2026 00:00:00 Z

Military medical experts align efforts, focus on warfighter readiness at annual military health worldwide symposium

Top Department of War leaders delivered a unified vision of advancing warfighter readiness and enhancing military health during the opening of the 2026 Military Health System Conference, in Dallas, Texas, May 27.

The core of the MHS is the operational readiness and health of the warfighter, said Anthony J. Tata, Department of War undersecretary for personnel and readiness.

“Everything that comes out of this giant organization comes down to the very tip of the spear where that medic with an aid bag must apply lifesaving measures to somebody who's wounded,” Tata said.

Tata and Keith Bass, assistant secretary of war for health affairs, addressed a capacity crowd of 2,600 service members, Department of War personnel, and government and industry healthcare professionals, gathering under the theme of “Military Health: Delivering Readiness, Driving Innovation, and Strengthening Partnerships.”

The four-day event serves as the premier Military Health System venue for knowledge sharing, discussing lessons learned across the enterprise, and introducing new developments aimed at making the MHS a global vanguard of an integrated health system.

Building a pipeline of talent for warfighter care

In his remarks, Tata, who commanded at several levels during 28 years in the U.S. Army, emphasized that high-level administrative decisions must always be grounded in dedicated support of the warfighter.

The Under Secretary of War for Personnel and Readiness Anthony J. Tata serves as the opening speaker at the 2026 Military Health System Conference in Dallas, Texas, May 27. The conference focused on "Military Health: Delivering Readiness, Driving Innovation, and Strengthening Partnerships,” and offered Department of War health care professionals and industry partners the opportunity to engage across the MHS as the Department seeks to become the world’s role model for an integrated health system.

“I approach every problem as a paratrooper battalion commander, thinking about that young 18-year-old paratrooper who just laced up his boots and got out of his harness and is moving out and drawing fire,” Tata said.

Recalling his time mapping out medevac routes in combat zones, he emphasized that warfighters relied on trusting they were supported by world-class care.

“I would gather my medics, and I would tell them our trigger pullers can go do what they're going to do only because they know you're going to get there in the golden hour,” he said.

His missions in the military reflect the vision for the MHS “to save the life of a wounded Soldier, Sailor, Airman, Marine. That's the essence of what we're talking about here,” he said.

Acknowledging the challenges of staffing across a massive global enterprise, Tata framed personnel retention not as a hurdle — but as an opportunity for unprecedented investment in people.

He introduced "Project Patriot Pipeline," a visionary initiative designed to retain highly trained personnel in critical fields like healthcare. By aligning tuition assistance, credentialing, and transition programs, the DOW aims to keep vital talent within the MHS.

“Project Patriot Pipeline is a big deal. It's all about aligning personnel policies,” he said.

“We're trying to bring in young men and women to serve in those key defense industrial base jobs for us ... high demand, low density, like healthcare," Tata said.

Rather than simply recruiting new talent, however, the program places a premium on long-term career progression and targeted financial incentives to keep service members in a field vital for warfighter readiness.

"And once they're in, we want to retain them, and so the bonuses are aligned to keep them in those high demand, low density skill sets," he concluded.

Reorienting healthcare as a tactical imperative

Bass, a retired U.S. Navy medical service corps officer and former Veterans Health Administration executive, firmly shifted the traditional view of military healthcare from a baseline support function to a critical tactical imperative. In his remarks, he underscored the true nature of conference attendees’ daily work.

"Our mission is readiness," Bass stated. "Our mission is to support the warfighter, and that's what we're going to focus on ... we have a no-fail mission."

To support this mission, Bass addressed what is required to sustain it. He noted the need for a "progressive plan to bring the right folks on board at the right times,” highlighting that the DOW values long-term talent cultivation and strategic placement over quick fixes.

That commitment to service members extends far beyond their active duty careers. Bass encouraged moving away from the mindset of a simple administrative handoff to the Department of Veterans Affairs after military service — advocating for a seamless, joint, continuum of care.

“We still have responsibility: obligation to support those individuals, and it should be from the time that you raise your right hand and enlist to the time that you finish with the VA, and everything in the middle,” Bass explained.

Addressing the challenge of maintaining clinical proficiency between conflicts — often referred to as the "Walker Dip" — Bass stressed the need for continuous medical evolution rather than relying on past tactics.

“The Walker Dip and that peacetime effect: We must mitigate that," Bass said. "But you don't fight the next war like you fight the last war. There are variations. We must adapt and make sure we're ready and we're prepared, and it should be a steady state of readiness.”

Ultimately, Bass stressed, maintaining this steady state of readiness requires prioritizing the MHS's role as a combat multiplier above standard military hospital and clinic operations.

Mission success: operational readiness

“We cannot negate or lose sight on the combat support agency mission," he emphasized. "We have made strategic investments in our blood program, joint trauma system, research, and medical logistics.”

Concluding the plenary, Bass reiterated the MHS mission to keep the warfighter healthy, safe, and ready, saying, “You must have medical readiness to support lethality and military capability.”

He then reminded the audiences why the 2026 MHS Conference was pivotal in mission success.

“Our job in this room is not to talk about the future of military medicine. Your job over the next two days is to shape the future of military medicine.”

Excellence in military medicine: ‘Your work saves lives and personifies readiness’

Thu, 14 May 2026 00:00:00 Z

Military medical leaders, professionals, and civilians who advance warfighter health were recognized at the Henry M. Jackson Foundation’s Heroes of Military Medicine Awards for “laying the next foundation stones, and reinforcing the very groundwork of military medicine for generations to come,” said Keith Bass, assistant secretary of war for health affairs.

“Your work saves lives and personifies readiness. The work we recognize this evening is not just invaluable — it is a cornerstone of our nation’s strength, safeguarding the health and well-being of our warfighters and their families,” Bass said at the annual ceremony held May 7, 2026, at the Washington National Cathedral in Washington, D.C.

The foundation’s annual awards recognize outstanding contributions of Military Health System personnel for their excellence and selfless dedication while serving the nation's wounded, ill, and injured service members, veterans, and civilians and their families.

Gen. Christopher Mahoney, the vice chairman of the Joint Chiefs of Staff, called warfighter health professionals “the quiet architects of our fighting force.”

“Military medicine is not a derivative of readiness. It's not adjacent to readiness. It is readiness,” stressed Mahoney. “You don't just patch wounds … you restore hope when we’re in the darkest corners of the earth. You carry the physical and emotional weight of our nation's sons and daughters, ensuring those who put everything on the line have a fighting chance to make it home.”

Heroes of military medicine honorees

“Today’s medical breakthroughs are built on the legacy of giants,” Bass said. “Tonight, we recognize six individuals who are boldly carrying that legacy forward.”

Medical professionals from the U.S. Army, U.S. Navy, U.S. Air Force, U.S. Coast Guard, U.S. Public Health Service, and the military medical civilian workforce were honored. They are:

U.S. Army: Maj. (Dr.) Erika Page

Page is an emergency medicine physician assigned to the 158th Maneuver Enhancement Brigade of the Arizona Army National Guard, and is a full-time emergency medicine physician in Tuba City, Arizona. She entered the National Guard as a direct commission in September 2021 with the rank of captain.

From October 2023 to July 2024, she was mobilized to Operation Spartan Shield in the U.S. Central Command area of operations with Task Force Sentinel. She served as the task force surgeon and medical operations officer throughout the deployment, overseeing the development of three physician assistants and the continuous operation of three Role 1s. In January 2024, she was the lead medical officer at Tower 22, Jordan, when a one-way drone attack resulted in three killed in action and over 70 wounded.

U.S. Navy: Chief Hospital Corpsman Robert Murphy

Murphy is currently assigned to Naval Warfare Advanced Training Command in Coronado, California, where he is the sole medical representative in the detachment.

Prior to his current assignment, he was the senior medical department representative with the Undersea Rescue Command, leading numerous international operations. Previously, he attended the Navy Diving and Salvage Training Center and the Naval Deep Sea Diving Independent Duty Corpsman School, served with the Undersea Rescue Command, and was stationed at SEAL Delivery Vehicle Team 1 in Pearl City, Hawaii.

U.S. Air Force: Lt. Col. (Dr.) Eric Meyer

Meyer is the chief medical officer, 52nd Medical Group, Spangdahlem Air Base, Germany. He is responsible for delivering $26 million in annual healthcare and directs a team of 18 personnel across safety, quality, credentialing, patient advocacy, case management, and healthcare integration.

Prior to his current assignment, Meyer served as the psychiatry consultant to the U.S. Air Force Surgeon General and the deputy director of Air Force Psychological Health at the Defense Health Headquarters. He has previously taught at the Uniformed Services University and served as the psychiatry clerkship director and neuroscience module director at the school.

He was inducted into the U.S. Army’s Order of Military Medical Merit and recognized as the Defense Health Agency’s Air Force Hero of Military Medicine in 2026.

U.S. Coast Guard: Capt. (Dr.) Joseph Perez

Perez serves as the acting chief of the United States Coast Guard’s Operational Medicine and Quality Improvement Division, acting USCG Atlantic Area Surgeon, and the chief medical officer of the USCG Health, Safety, Work Life Service Center. He also serves as the senior medical executive and chief medical officer of the USCG District 1 and the senior medical officer of the U.S. Coast Guard clinic in Sector, New York.

He is a family medicine physician, certified physician executive, and flight surgeon, and has served with the U.S. Public Health Service, U.S. Coast Guard, and the U.S. Navy. Perez has also supported assignments to the U.S. southwest border, Ebola screenings at U.S. airports, and medical efforts following the deadly earthquake in Haiti in 2010, and in Louisiana following Hurricane Katrina in 2005. He also helped stand up Camp Delta Clinic and care for detainees at Guantanamo Bay, Cuba, in support of Operation Enduring Freedom.

U.S. Public Health Service: Capt. (Dr.) Abby Shannon

Shannon is the senior dental executive at the U.S. Coast Guard training center in Cape May, New Jersey, where she is responsible for the dental health and readiness of boot camp recruits and active duty service members, and for the management of the dental program at the U.S. Coast Guard’s largest clinic.

She joined the USPHS while working at the Indian Health Service in Sisseton, South Dakota. She transferred to U.S. Coast Guard Training Center Cape May. She then served as the senior dental executive of the National Capital Region. In this position, she provided and coordinated comprehensive dental care to over 2,500 U.S. Coast Guard active duty and Reserve Component members across 22 units, 23 detached units, 17 individual directorates, and 14 U.S. embassies, while also supervising care at the U.S. Coast Guard Yard dental clinic.

Civilian: Dr. James Quinn

Quinn is the associate program director of the Allergy/Immunology Fellowship at the San Antonio Uniformed Services Health Education Consortium, one of the largest and most respected allergy/immunology programs in the country. He has trained over 80 allergy and immunology fellows who have maintained the program’s 100% board pass rate since 1995. A professor of medicine at USU, he has received board certification in internal medicine, allergy/immunology, and clinical laboratory immunology. Following his retirement in 2009, he serves as a public servant at Wilford Hall Ambulatory Center.

With more than 60,000 civilians working in military medicine, noted Vice Adm. Darin Via, director of the DHA, “Quinn is a model of what our quiet civilian medical heroes look like. An expert in his field, researcher, author, speaker, above all, mentor, and teacher.”

Acknowledging excellence for the warfighter

Mahoney concluded the ceremony by emphasizing the work of these professionals is the “lifeblood of the joint force.”

“Tonight is not just about thanking you for your science, it’s about acknowledging the fundamental truth: Without your relentless dedication, the rest of us could not do our jobs,” he said.

Update: Heat exhaustion and heat stroke among U.S. active component service members, 2021–2025

Fri, 01 May 2026 00:00:00 Z

Abstract

In 2025, the unadjusted incidence rates of heat stroke and heat exhaustion among U.S. active component service members were 39.4 and 170.0 cases per 100,000 person-years, respectively. The rate of heat stroke increased in 2024 and 2025, after declining for 3 years (2021-2023) at the beginning of the 5-year surveillance period. In contrast, the rate of heat exhaustion decreased in 2025, following a 4-year increase from 2021 through 2024. In 2025, male service members experienced higher rates of heat stroke, when compared to their female counterparts. Female service members and non-Hispanic Black service members experienced higher rates of heat exhaustion than their male counterparts and service members of other racial and ethnic groups, respectively. Consistent with prior annual reports, heat illness rates remained the highest among those younger than age 20 years, Marine Corps and Army members, and recruit trainees. To protect the force and increase readiness, military leaders and public health personnel can implement evidence-based prevention strategies, train service members to recognize the signs and symptoms of heat illness and take early action to counter the threat.

What are the new findings?

The unadjusted incidence rate of heat stroke increased 6.9% from 2024 to 2025, for the second year in a row, while the unadjusted annual incidence rate of heat exhaustion fell by 9.1% in 2025, following a 4-year increase from 2021 through 2024. Locations where entry training are conducted for new Army, Air Force, Marine Corps, and Space Force personnel accounted for 40.3% of all heat illness diagnoses over the 5-year surveillance period. Training, specifically initial training upon service entry, remains a major risk factor for heat illness occurrence among U.S. active component service members.

What is the impact on readiness and force health protection?

Heat exhaustion and heat stroke can both be prevented through situational awareness, application of appropriate risk management strategies, and, when necessary, effective countermeasures. Units that fail to implement heat illness mitigation measures risk impeding or interrupting training programs, leading to reduced operational tempo or critical mission failure due to lost personnel and resources.

Background

The most serious types of heat illnesses, heat exhaustion and heat stroke, are occupational hazards associated with many of the military’s training and operational environments, posing potential risks for force health protection. Heat illness refers to a group of disorders that result from a disruption of thermoregulation caused by high energy expenditure (i.e., metabolic heat production), environmental heat exposure, or a combination of both factors.^1-4

Heat illness occurs within a continuum of severity, from less severe (e.g., heat cramps, rash, edema), to heat exhaustion, followed by potentially life-threatening heat stroke.⁵ Heat exhaustion and heat stroke are reportable medical events (RMEs) in the Military Health System (MHS) to the Disease Reporting System internet (DRSi). All heat casualties that require medical intervention or result in change of duty status must be reported by U.S. Armed Forces installation public health personnel.⁶

During or immediately following a period of physical exertion or heat exposure, specific signs and symptoms that characterize heat illnesses allow initial recognition of their occurrence in the field, and subsequent identification or diagnosis of a heat illness that should be reported. Common signs and symptoms of heat exhaustion include weakness, muscle cramps, headache, dizziness, nausea or vomiting, tachycardia, and short-term physical collapse or debilitation. Heat exhaustion is often characterized by elevated core body temperature (greater than 100.5 °F [38 °C], but not greater than 104 °F [40 °C]) with no significant central nervous system dysfunction. If central nervous system dysfunction develops (e.g., dizziness, confusion, headache), it should be mild and rapidly resolve with rest and cooling measures, otherwise the individual may be experiencing heat stroke.^7-10

Heat stroke is a debilitating and potentially life-threatening condition most frequently characterized by evidence of severe hyperthermia (greater than or equal to 104 °F [40 °C]) and central nervous system dysfunction that can include change in mental status, delirium, stupor, loss of consciousness, or coma.^7-9,11 Onset of heat stroke should prompt aggressive intervention featuring rapid cooling, such as cold water immersion and iced sheets.^12-14 The literature on heat stroke management indicates consensus on prioritizing cooling over transportation for further medical attention.^11,13,15,16 Cooling is prioritized because, clinically, severity of end-organ damage and increased possibility of mortality are directly related to the degree and duration of hyperthermia.^8,14,16 End-organ damage due to heat stroke is most frequently observed in the liver, kidneys, cardiac and skeletal muscle.^8,11,15,17

While temperature and humidity are well recognized environmental risk factors for heat illness, there are individual, occupational, and organizational risk factors that influence heat illness occurrence. Individual risk factors include lack of acclimatization, physical fitness levels, pre-existing or recent viral illness, body composition, and personal motivation to excel.^7,12 Organizational factors include type of activity, training intensity and duration, and training schedules.^7,12 These risk factors do not work independently of each other; there is literature that suggests risk factors interact to increase risk of heat illness, making it essential that military leaders and service members recognize the full spectrum of potential factors in a training or operational environment.¹⁸ For example, metabolic heat production increases during prolonged engagement in strenuous physical activity, and additional exposure to environmental heat stress elevates core and skin temperatures.^2,3,8

Identifying high-risk service members is critical for preventing heat illness and reducing morbidity due to heat illnesses.¹⁹ Early detection reduces heat illness morbidity and severity and requires educating service members and leadership on the signs and symptoms of heat illness in addition to the incorporation of physiological monitoring, managing exceptional individuals during training (i.e., establishing minimum or maximum pacing), and removing service members from high-risk events. Heat illness mitigation strategies should be implemented for individuals as well as organizations, using a tiered risk management model.¹³ To achieve hazard reduction, progressive training, heat acclimatization, along with ensuring proper hydration, electrolyte replacement, and nutrition before training can prepare individual service members for training and operating in high heat environments.^3,20 Risk mitigation strategies that can be instituted during training activities include adherence to work and rest guidelines, modified clothing and uniform standards, individual- or group-pacing during high-risk events (e.g., timed ruck marches), climate-adapted schedules or activities, and available cooling measures (e.g., arms immersion cooling or microclimate cooling).^13,14,20

Surveillance of heat illnesses is necessary to evaluate whether prevention guidelines and countermeasures are working, in addition to identifying high-risk groups and activities that may lead to heat illness. Since 2011, MSMR has published regular updates on the incidence of heat illness among U.S. active component service members (ACSMs). This update presents summaries of heat stroke and heat exhaustion case counts, incidence rates, and locations from 2021 through 2025.

Methods

The surveillance population for this analysis includes all individuals who served in the active component of the Army, Navy, Marine Corps, Air Force, Space Force, or Coast Guard at any time during the surveillance period of January 1, 2021 through December 31, 2025. Space Force data are only complete for 2023 through 2025.

All data used to determine incident heat illness diagnoses were derived from 4 sources: MHS Management, Analysis and Reporting Tool (M2), Defense Medical Surveillance System (DMSS), DRSi, and Theater Medical Data Store (TMDS). Heat illness cases were identified using specific diagnostic codes from the ambulatory care encounters and hospitalizations of ACSMs in fixed military and civilian (if reimbursed through the MHS) hospitals and clinics worldwide. In addition to medical encounter data, heat illness medical event reports were identified in DRSi, including information on hospitalization status (i.e., ‘yes’ or ‘no’). If a heat illness was reported in DRSi, but not found in the medical record, the case was still counted. For example, an individual could be treated in the field by a medic for a mild or non-life-threatening heat illness without a recorded medical encounter, but the case is deemed a reportable heat exhaustion because of symptoms observed in the field.

In this update, a case of heat illness was defined as an individual with 1) a hospitalization or outpatient medical encounter record with a primary (first-listed) or secondary (second-listed) diagnosis of heat stroke (International Classification of Diseases, 9th Revision [ICD-9]: 992.0; International Classification of Diseases, 10th Revision [ICD-10]: T67.0*) or heat exhaustion (ICD-9: 992.3–992.5; ICD-10: T67.3*–T67.5*) or 2) a RME record of heat exhaustion or heat stroke.¹⁹ Asterisks denote that all subsequent digits or characters noted in that diagnostic code were included in the identification of ICD-10 codes (e.g., T67.3XXA).

An individual was considered a case of heat illness only once per year. If a service member had diagnoses for both heat stroke and heat exhaustion during a given year, the more severe diagnosis (i.e., heat stroke) was selected. If a service member had inpatient and outpatient encounters for heat stroke or heat exhaustion, the inpatient encounter was prioritized over the outpatient visit, when identifying hospitalized cases. Within a calendar year, if an individual had a diagnostic code that denoted a subsequent encounter (i.e., ICD-10 seventh digit ‘D’) or an encounter for sequelae (i.e., ICD-10 seventh digit ‘S’), but had no diagnostic codes indicating an initial visit (i.e., ICD-10 seventh digit ‘A’), the case was removed to avoid over-estimating heat illness cases by including those receiving follow-up care.

For health surveillance purposes, recruit trainees were identified as ACSMs assigned to service-specific training locations and basic training periods, using an algorithm based on age, rank, and time in service. Recruit trainees were considered a separate enlisted service member category in heat illness summaries by military grade. In summaries of heat illness by location, the Defense Medical Information System Identifier (DMIS ID) was used to determine installation or geographic location of diagnosis and medical treatment.

In-theater diagnoses of heat illness were identified from medical records of deployed service members whose health care encounters were documented in TMDS. Those encounters were analyzed separately, and the same case-defining criteria and incidence rules described previously were applied.

Incidence rates (IRs) were calculated as incident cases of heat illness per 100,000 ACSM person-years (p-yrs). Percent change in IRs was calculated using unrounded rates. Because reporting heat exhaustion and heat stroke cases is required, the proportion of outpatient and inpatient cases with a report in DRSi was also calculated.⁶

Results

In 2025, 518 cases of heat stroke occurred throughout the MHS, resulting in an unadjusted IR of 39.4 cases per 100,000 p-yrs (Table 1). Recruit trainees, Marine Corps and Army personnel, and service members younger than age 20 years experienced the highest subgroup-specific IRs of heat stroke, as well as those in combat-specific occupations. Service members of different races and ethnicities had similar rates of heat stroke. The rate of heat stroke was 76.2% higher among men (42.8 cases per 100,000 p-yrs) compared to women (24.3 cases per 100,000 p-yrs). Recruit trainees experienced rates of heat stroke 3.5 and 3.1 times higher than other enlisted service members and officers, respectively.

In 2025, the unadjusted annual incidence of heat stroke increased 6.9% compared to the IR in 2024 (Figure 1). In 2025 IRs of heat stroke increased among service members in the Army (21.1%) and Marine Corps (6.3%) but decreased among service members in the Air Force (-24.5%) and Navy (-51.0%) (Table 2). The proportion of hospitalized heat stroke cases increased slightly, to 38.6% in 2025, from 35.9% in 2024 (Figure 1). Of all inpatient heat stroke cases from 2021 through 2025, 78.7% had a medical event report in DRSi, compared to 60.5% of outpatient heat stroke cases.

The 2,233 cases of heat exhaustion in 2025 correspond to an unadjusted IR of 170.0 cases per 100,000 p-yrs (Table 1). As with heat stroke, rates of heat exhaustion remained highest for service members younger than age 20 years, Marine Corps and Army personnel, and recruit trainees. Unlike heat stroke, however, the rate of heat exhaustion was higher among women (15.8% higher compared to men) and non-Hispanic Black service members (27.4% higher compared to non-Hispanic White service members). Recruit trainees experienced rates of heat exhaustion 9.4 and 18.1 times higher than other enlisted service members and officers, respectively.

After increasing in the previous 4 years, in 2025 the unadjusted annual incidence of heat exhaustion decreased 9.1% compared to 2024. Service-specific rates of heat exhaustion decreased in 2025 among Marine Corps (-28.6%), Air Force (-16.7%), and Army personnel (-1.6%) compared to the rates observed in 2024 (Table 2). The proportion of hospitalized heat exhaustion cases in the U.S. Armed Forces remained small (4.5%) (Figure 2). Three-quarters (75.6%) of inpatient heat exhaustion cases had reports in DRSi from 2021 to 2025, while only 38.2% of outpatient heat exhaustion cases had a medical event report.

Heat illnesses by location

During the 5-year surveillance period, at more than 300 military installations and geographic areas worldwide, a total of 13,047 heat illness cases were diagnosed among ACSMs (Table 3). Only 7.5% of those heat illness cases occurred outside the U.S., including 409 in Okinawa, Japan. From 2021 to 2025, 21 locations reported at least 100 cases of heat illness, and those 21 locations accounted for over three-quarters (75.4%) of all ACSM cases. The 4 Army installations (Fort Benning, GA; Fort Jackson, SC; Fort Leonard Wood, MO; Fort Sill, OK), 2 Marine Corps bases (Marine Corps Recruit Depot [MCRD] Parris Island/Beaufort, SC and MCRD San Diego/NB San Diego, CA) and 1 Joint Base (JB San Antonio, TX) where initial entry training occurs accounted for 40.3% of the heat illnesses during the surveillance period. Of the 21 locations with at least 100 cases of heat illness, 14 are in the southern U.S.

In-theater diagnosis of heat illness

During the 5-year surveillance period, 404 cases of heat illness occurred in-theater, with the highest number reported in 2025 (Figure 3). Heat stroke cases accounted for 7.4% (n=30) of those 404 cases of heat illness. Cases of heat illness occurred most frequently among deployed ACSMs who were male (n=295, 73.0%), ages 20-24 years (n=194, 48.0%), and in the Navy (n=230, 56.9%) (data not shown).

Discussion

During the 5-year surveillance period, the rate of total heat illness diagnoses increased annually from 2021 through 2024 and then decreased by 6.4% in 2025. The 2025 decrease was driven by a 9.1% decrease in the rate of heat exhaustion among ACSMs in 2025 compared to 2024. The decreased IR of heat exhaustion was most prominent among Marine Corps and Air Force ACSMs. The rate of heat stroke increased by 6.9% during the same period, however, with rising IRs among Army and Marine Corps personnel.

To support the surveillance of heat illnesses among the U.S. Armed Forces, reporting heat exhaustion and heat stroke cases to DRSi is required.⁶ As in previous reports, the proportion of heat exhaustion cases reported in 2025 to DRSi was substantially lower than the proportion of heat stroke cases reported (40.0% versus 77.4%, respectively). The proportion of heat stroke cases being reported to DRSi continues to improve, however, with the highest frequency of cases reported in 2025. The Armed Forces Reportable Medical Events Guidelines and Case Definitions provides military Preventive Medicine and Public Health departments with the criteria for reporting these cases to DRSi.⁶

There are limitations to this update that should be considered when interpreting its findings. Although heat illnesses were summarized by the location of diagnosis or report, medical care may not occur at the same location (i.e., installation or base) as the heat illness event, particularly if the case required a level of care not available locally. To account for locations with medical care redundancy, some installations were combined (e.g., MCB Camp Lejeune/Cherry Point, NC in Table 3); this merging of locations was most prevalent with Marine Corps and Navy locations. Further, the method used to identify recruit trainees likely resulted in some misclassification of recruit training status. The algorithm did not account for the additional training time in the Army’s One Station Unit Training beyond the traditional basic combat training period and does not account for service members who are recycled through training, likely leading to an under-estimation of the heat illnesses among recruit trainees. Finally, there was likely incomplete capture of heat illnesses treated in the field during training and deployments, rather than at a fixed military hospital or clinic; this may be particularly true for heat exhaustion cases when symptoms rapidly resolve after a period of rest.

Heat illness surveillance helps military public health and leadership understand the impact these conditions have on service member health, training, and force readiness. To mitigate the personal and organizational impacts of heat illness, leaders, training cadres, and supporting medical and safety personnel must inform both their subordinate and supported service members of heat illness risks, preventive measures, early signs and symptoms of illness, and appropriate interventions. To preserve readiness and protect military personnel, Department of War standards, policies, or guidelines should support heat illness surveillance coupled with evidence-based prevention, mitigation, and management practices.

References

Carter R, Cheuvront SN, Williams JO, et al. Epidemiology of hospitalizations and deaths from heat illness in soldiers. Med Sci Sports Exerc. 2005;37(8):1338-1344. doi:10.1249/01.mss.0000174895.19639.ed
Hancock PA, Ross JM, Szalma JL. A meta-analysis of performance response under the thermal stressors. Hum Factors. 2007;49(5):851-877. doi:10.1518/001872007x230226
Headquarters, Department of the Army. Heat Stress Control and Heat Casualty Management. Technical Bulletin, Medical, 507. Apr. 12, 2022. Accessed Mar. 18, 2026. https://www.govinfo.gov/content/pkg/GOVPUB-D101-PURL-gpo216616/pdf/GOVPUB-D101-PURL-gpo216616.pdf
Atha WF. Heat-related illness. Emerg Med Clin North Am. 2013;31(4):1097-1108. doi:10.1016/j.emc.2013.07.012
Armed Force Health Surveillance Branch. Surveillance Case Definition: Heat Illness. Defense Health Agency, U.S. Department of War. Accessed Mar. 18, 2026. https://health.mil/reference-center/publications/2019/10/01/heat-injuries
Armed Forces Health Surveillance Branch, U.S. Air Force School of Aerospace Medicine, Army Public Health Center, Navy and Marine Corps Public Health Center. Armed Forces Reportable Medical Events Guidelines and Case Definitions, October 2022. Defense Health Agency, U.S. Department of War. Accessed Mar. 18, 2026. https://www.health.mil/military-health-topics/health-readiness/public-health/afhsd/reports-and-publications/armed-forces-reportable-medical-events
Alele FO, Bunmi SM, Aduli EOM, Crow MJ. Epidemiology of exertional heat illness in the military: a systematic review of observational studies. Int J Environ Res Public Health. 2020;17(19):7037. doi:10.3390/ijerph17197037
Danzig RM, Raunig JM, Acholonu CJ. Exertional heat illness: from identifying heat rash to treating heat stroke. Pediatr Ann. 2024;53(1):e17-e21. doi:10.3928/19382359-20231113-04
Buller MJ, Delves SK, Fogarty AL, Veenstra BJ. On the real-time prevention and monitoring of exertional heat illness in military personnel. J Sci Med Sport. 2021;24(10):975-981. doi:10.1016/j.jsams.2021.04.008
O’Connor FG, Sawka MN, Deuster P. Disorders due to heat and cold. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Elsevier Saunders;2016:692-693.
Epstein Y, Yanovich R. Heatstroke. NEJM. 2019;380(25):2449-2459. doi:10.1056/nejmra1810762
Lalli K, Charkoudian N, Moreh Y, DeGroot D. The role of motivation to excel in the etiology of exertional heat stroke. J Spec Oper Med. 2024;24(2):28-33. doi:10.55460/4tiv-hqlo
Epstein Y, Charkoudian N, DeGroot DW, et al. Exertional heat illness: international military-oriented lessons learned and best practices for prevention and management. Front Physiol. 2025;16:1456984. doi:10.3389/fphys.2025.1456984
Wood F, Roiz-de-Sa D, Pynn H, et al. Outcomes of UK military personnel treated with ice cold water immersion for exertional heat stroke. BMJ Mil Health. 2024;170(3):216-222. doi:10.1136/military-2022-002133
Koo CJ, Hintz C, Butler CR. Return to duty following exertional heat stroke: a review. Mil Med. 2024;189(5-6):e1312-e1317. doi:10.1093/milmed/usad388
Wilcox MJ, Rhodehouse BB, DeGroot DW. Ice sheet cooling in the field reduces morbidity in exertional heat stroke. Curr Sports Med Rep. 2024;23(4):119-123. doi:10.1249/jsr.0000000000001156
Goodwin KC, Giersch GEW, Murray TA, DeGroot DW, Charkoudian N. Sex differences in biomarkers of end-organ damage following exertional heat stroke in humans. J Appl Physiol. 2024;137(5):1434-1445. doi:10.1152/japplphysiol.00463.2024
Kazman JB, Nelson DA, Ahmed AE, et al. Risk for exertional heat illness among US army enlistees: climate indexes, intrinsic factors and their interactions. Br J Sports Med. 2025;59(4):231-240. doi:10.1136/bjsports-2024-108441
Bureau of Medicine and Surgery, Navy Environmental Health Center. Prevention and Treatment of Heat and Cold Stress Injuries Technical Manual NEHC-TM-OEM 6260.6A. Department of the Navy, U.S. Department of War. Jun. 2007. Accessed Mar. 18, 2026. https://www.med.navy.mil/portals/62/documents/nmfa/nmcphc/root/occupational%20and%20environmental%20medicine/5heat_and_cold_final_june07.pdf
Roberts WO, Armstrong LE, Sawka MN, et al. ACSM expert consensus statement on exertional heat illness: recognition, management, and return to activity. Curr Sports Med Rep. 2021;20(9):470-484. doi:10.1249/jsr.0000000000000878

Authors’ Affiliation

Disease Epidemiology Program, Defense Centers for Public Health–Aberdeen, Defense Health Agency, Aberdeen Proving Ground, MD

Disclaimer

The views expressed in this report reflect the results of research conducted by the authors and do not necessarily reflect official policy nor position of the Defense Health Agency, Department of War, or the U.S. Government. The mention of any non-federal entity or its products is for informational purposes only, and is not to be construed or interpreted, in any manner, as federal endorsement of that non-federal entity or its products.

Update: Exertional hyponatremia among U.S. active component service members, 2021–2025

Fri, 01 May 2026 00:00:00 Z

Abstract

Exertional hyponatremia, also known as exercise-associated hyponatremia, is a fluid electrolyte disorder defined by a low sodium level in the blood (below 135 mEq/L). Exertional hyponatremia results from excessive fluid intake that dilutes serum sodium, impairing neurological and other organ functions. Hyponatremia can be fatal if not detected early and managed properly. From 2021 through 2025, 609 cases of exertional hyponatremia were diagnosed among U.S. active component service members (ACSMs), with an overall incidence rate of 9.2 cases per 100,000 person-years (p-yrs). In 2025, 106 cases of exertional hyponatremia were diagnosed among ACSMs, resulting in an incidence rate of 8.1 per 100,000 p-yrs. The highest incidence rates in 2025 were observed among males, individuals ages 35-39 years, non-Hispanic White service members, those in health care occupations, and personnel stationed in the western U.S. Notably, between 2024 and 2025 the Marine Corps and recruit populations showed a sharp decline in cases. From 2021 to 2023, annual rates of incident exertional hyponatremia diagnoses increased, peaking in 2023 (11.6 per 100,000 p-yrs) and then decreased to 8.1 cases per 100,000 p-yrs in 2025. Although the incidence of exertional hyponatremia is decreasing, continued monitoring and specialized prevention strategies are critical, as the associated risk factors may affect individuals differently.

What are the new findings?

Incidence rates of exertional hyponatremia decreased from 10.6 per 100,000 people per year in 2024 to 8.1 per 100,000 in 2025. Rates increased sharply in the 35-39-years age group, however, while decreasing sharply among those younger than age 20 years, ages 25-29 years, and in the Marine Corps.

What is the impact on readiness and force health protection?

The recent decline in cases of exertional hyponatremia is positive, but shifting rates among demographic groups show that risks are still dynamic. Due to the fact exertional hyponatremia can be fatal, commanders and trainers should prioritize enforcement of proper hydration protocols, maintain vigilance to identify early symptoms, and if necessary ensure immediate, prescribed intervention.

Background

Exertional hyponatremia is a fluid electrolyte disorder resulting from excessive consumption of hypotonic fluids such as water. Although exertional hyponatremia is relatively rare, it can be fatal if not detected early and managed properly. Exertional hyponatremia is caused by increased consumption of hypotonic fluids, such as water or sports drinks, before or during strenuous physical activity, such as prolonged military field training and combat operations. Active component military personnel are particularly susceptible to fluid and electrolyte imbalances due to intense exertion and demanding physical activities.^1,2 Key individual risk factors besides excessive fluid intake include exercise lasting more than 4 hours, inadequate training, and a high or low body mass index.³ Risk of exertional hyponatremia is influenced by a range of factors, including the duration and type of activity—from military exercises to endurance races—as well as environmental conditions such as heat stress and water availability.

The severity and onset of exertional hyponatremia symptoms depend on the rate and degree of the decrease in serum sodium from normal levels. When a serum or plasma sodium concentration is less than 135 milliequivalents per liter (mEq/L) within 24 hours after prolonged physical activity, hyponatremia or exertional hyponatremia occur. Normal plasma sodium concentration (Na+) is closely regulated between 135 and 145 mEq/L to maintain proper cell size and function.¹ Excessive intake of sodium will stimulate thirst to increase body water to maintain normal sodium serum concentration.^4,5 Exertional hyponatremia can also be caused by inappropriate secretion of a non-osmotic antidiuretic hormone due to physical exertion, resulting in increased total body and free water retention.⁶

Symptoms of exertional hyponatremia, which can manifest during or after physical activity, range from mild to life-threatening. Mild symptoms include lightheadedness, malaise, fatigue, irritability, weakness, headache, nausea, and reduced urine excretion. Severe symptoms can escalate to vomiting, oliguria or anuria, altered mental status, collapse, seizures, coma, and death.⁶ Hyponatremia is treated primarily by managing the underlying cause and free water restriction,⁷ focusing on pre-hospital care through rapid on-site emergency medical service assessment, as well as emergency and inpatient hospital management.⁸ Depending on the physical demands of military operations and prevailing environmental conditions, replacement fluid composition may vary.⁹

Hyponatremia is particularly problematic in the military, where it can be mistaken for an exertional heat illness (EHI), such as heat exhaustion or heat stroke, with corresponding symptomology that makes differential diagnosis difficult.⁸ Exertional hyponatremia must be differentiated from EHI to avoid inappropriate treatment and adverse outcomes.¹⁰ Failure to differentiate between these conditions can lead to incorrect treatment including overhydration, which risks severe and potentially permanent neurological damage.¹¹

The fundamental characteristics of military operations, such as long-term military training and combat operations in extreme environmental conditions, mean that exertional hyponatremia continues to pose a health risk to U.S. military personnel, with the potential for significantly reducing performance and combat effectiveness. There is growing evidence that hyponatremia is associated in various clinical settings and diseases with increased morbidity, mortality, and health costs.^12-14 MSMR annually summarizes the numbers, rates, trends, risk factors, and locations of exertional heat injury occurrences including exertional hyponatremia. This report includes updated surveillance data from 2021 through 2025. Additional information about the definition, causes, and prevention of exertional hyponatremia can be found in previous issues of MSMR.¹⁴ This report summarizes the frequency, rates, trends, demographic, geographic location, and military characteristics of exertional hyponatremia cases among U.S. active component service members (ACSMs) from 2021 to 2025.

Methods

The surveillance period ranged from January 2021 through December 2025 and included all individuals who served in the active component of the U.S. Army, Navy, Air Force, Marine Corps, Space Force, or Coast Guard. All data used to determine incident exertional hyponatremia diagnoses were derived from records routinely collected and maintained in the Defense Medical Surveillance System (DMSS). Those records document both ambulatory encounters and hospitalizations of U.S. Armed Forces ACSMs in fixed military and civilian (if reimbursed through the Military Health System) hospitals and clinics worldwide.

A case of exertional hyponatremia was defined as an individual with 1) a hospitalization or ambulatory visit with a primary (first-listed) diagnosis of “hypo-osmolality and/or hyponatremia” (International Classification of Diseases, 9th and 10th revisions, ICD-9: 276.1, ICD-10: E87.1) and no other illness or injury-specific diagnoses (ICD-9: 001–999, ICD-10: ‘A’–‘U’) in any diagnostic position or 2) both a diagnosis of ‘hypoosmolality and/or hyponatremia’ (ICD-9: 276.1, ICD-10: E87.1) and at least 1 of the following within the first 3 diagnostic positions (dx1–dx3): ‘fluid overload’ (ICD-9: 276.9; ICD-10: E87.70, E87.79), ‘alteration of consciousness’ (ICD-9: 780.0*, ICD-10: R40.*), ‘convulsions’ (ICD-9: 780.39, ICD-10: R56.9), ‘altered mental status’ (ICD-9: 780.97, ICD-10: R41.82), ‘effects of heat/light’ (ICD-9: 992.0–992.9, ICD-10: T67.0*–T67.9*), or ‘rhabdomyolysis’ (ICD-9: 728.88, ICD-10: M62.82).¹⁵

Medical encounters were excluded from case-defining events if the associated records listed diagnoses in any diagnostic position that included alcohol or illicit drug abuse; psychosis, depression, or other major mental disorders; endocrine disorders; kidney diseases; intestinal infectious diseases; cancers; major traumatic injuries; or complications of medical care. An individual could be considered a case of exertional hyponatremia only once per calendar year. Incidence rates were calculated as cases of hyponatremia per 100,000 person-years (p-yrs) of active component service. For health surveillance purposes, recruits were identified as active component members assigned to service-specific training locations during coincident service-specific basic training periods. Recruits were considered as a separate category of enlisted service members in summaries of exertional hyponatremia by military grade overall. Incidence rates reported in this update represent unadjusted rates.

Results

In 2025, a total of 106 cases of exertional hyponatremia were identified among ACSMs, corresponding to an incidence rate (IR) of 8.1 per 100,000 p-yrs, a noteworthy decrease from 10.6 per 100,000 p-yrs in 2024. The IR of 8.1 recorded in 2025 represents the lowest annual rate for the entire 2021–2025 surveillance period, just 2 years after the peak in incidence, 11.6 per 100,000 p-yrs, in 2023. From 2021 through 2025, 609 incident cases of exertional hyponatremia were reported among ACSMs, resulting in an overall IR of 9.2 cases per 100,000 p-yrs. During the 5-year surveillance period, 91.8% (n=559) of all cases were diagnosed and treated without hospitalization (data not shown). Figure 1 displays the annual incident cases and rates among ACSMs.

Although the Marine Corps had the highest overall IR (12.6 per 100,000 p-yrs) from 2021 to 2025, the Marine Corps rate dropped significantly between 2024 and 2025, from 17.0 to 7.6 per 100,000 p-yrs. While the annual IRs in the Army had been trending upward from 2022 to 2024, the IR for this service branch also declined in 2025 (Figure 3).

Incidence of exertional hyponatremia among recruits showed a sharp decline, of 64.8%, from 2024 to 2025, dropping from 49.9 cases per 100,000 p-yrs to 17.6 per 100,000 p-yrs. Only 5 cases of hyponatremia were recorded among recruits in 2025 (Table 1). The trend aligns with the overall pattern of case occurrence, which peaked in 2023 before shifting downward (data not shown).

In 2025, the highest occupational IRs were found in the health care (14.4 per 100,000 p-yrs) and pilot and air crew (11.5 per 100,000 p-yrs) military professions; no cases were reported in motor transport. Although the overall trend has declined since its peak in 2023, the rates for health care as well as pilot and air crew occupations have continued to rise (data not shown).

In 2025, service members ages 35-39 years had the highest IR for exertional hyponatremia, followed by those ages 40 years and older (18.3 and 17.3 per 100,000 p-yrs, respectively). The IR for the 35-39-years age group increased noticeably in 2025 compared to 2024, to 18.3 from 7.2 per 100,000 p-yrs, respectively. Since 2023, the incidence of exertional hyponatremia has decreased for all age groups except the 30-39-years group (data not shown).

For both male and female ACSMs, cases of exertional hyponatremia declined in 2025 from the previous year. There was no significant difference in the annual IRs of male and female ACSMs in 2025: 8.1 and 8.0 per 100,000 p-yrs, respectively. While the IRs of hyponatremia for both sexes decreased from 2024 to 2025, the drop was more significant for women. The female IR fell by 35.0% (from 12.3 to 8.0 per 100,000 p-yrs), compared to a 20.6% decrease in the male IR (from 10.2 to 8.1 per 100,000 p-yrs). This higher variability in female rates was evident in all observed periods (Figure 3).

From 2024 to 2025, the IRs of exertional hyponatremia declined among all racial and ethnic groups, excluding the ‘other or unknown’ category. The most substantial decrease was among Hispanic ACSMs, followed by non-Hispanic White and non-Hispanic Black service members. Notably, the trend for non-Hispanic White ACSMs had been increasing until 2024, when it began to decline. For all other ethnic groups, the decline in IRs started in 2023 (data not shown).

ACSMs stationed in the western U.S. exhibited a higher IR of exertional hyponatremia in 2025 compared to their counterparts in other regions, whereas other duty stations including the northeast, midwest, and southern regions showed similar IRs (data not shown). Exertional hyponatremia cases were diagnosed at more than 103 U.S. military installations and geographic locations worldwide during the surveillance period, but 12 U.S. installations contributed 7 or more cases each and accounted for 45.6% of total cases (Table 2). Fort Benning, Georgia, reported 48 cases of exertional hyponatremia, the highest in the Department of War.

Discussion

Since 2023, overall IRs of exertional hyponatremia among U.S. ACSMs have been on a downward trend, with substantial decreases in incidence among Marine Corps members, recruits, those in motor transport occupations, individuals ages 25-29 years, and female service members. Air Force exertional hyponatremia IRs were more variable throughout the 5-year surveillance period.

With the exception of the Air Force, all branches of service evinced downward trends in exertional hyponatremia IRs from 2024 to 2025. Marines and recruits demonstrated particularly sharp declines in exertional hyponatremia cases from 2024 to 2025.

In 2025, incidence of exertional hyponatremia declined for all military occupations, with 2 notable exceptions: health care personnel and pilots and air crew, which had the highest and second-highest IRs, respectively.

Exertional hyponatremia IRs in 2025 decreased among all age groups except for ACSMs ages 30-39 years. The most significant decline was seen in the 25-29-years age group, followed by the 20-24-years age group. A sharp surge in the IR for the ages 35-39-years group reversed the 2024 trend, where the ages 40 years and older group had the highest rate.

In 2022 and 2023, non-Hispanic Black service members had higher IRs, while in 2024 and 2025, non-Hispanic White service members had higher rates. Rates are comparable, however, among racial and ethnic groups. Risk is not definitively linked to any single ethnic group.^16-18

The IR for hyponatremia in the western U.S. increased in 2025 to become the highest in the nation. Notably, this region contains major military training centers in desert environments, such as the National Training Center at Fort Irwin, California, and the Marine Corps Air Ground Combat Center at Twentynine Palms, California. This report did not assess the intensity of military training or specific climate exposures during the reporting period, however. Consequently, no conclusions can be drawn about the impact of these operational and environmental factors on the observed increase.

Several important limitations should be considered when interpreting the results of this analysis. First, there is no diagnostic code specific for exertional hyponatremia. This lack of specificity may result in inclusion of some non-exertional cases of hyponatremia, thus overestimating the true rate. Consequently, the results of this analysis should be considered estimates of the actual incidence of symptomatic exertional hyponatremia from excessive water consumption among U.S. military members.

In addition, the accuracy of estimated numbers, rates, trends, and correlates of risk depends on the completeness and accuracy of diagnoses that are documented in standardized records of relevant medical encounters. Nonetheless, the decline in the number of diagnoses presenting with exertional hyponatremia may reflect increased awareness, concern, and aggressive management of early cases by military supervisors and primary health care providers. Finally, recruits were identified using an algorithm based on age, rank, location, and time in service, which was only an approximation and likely resulted in some misclassification of recruit training status.

The downward-trending IR for hyponatremia during the surveillance period may be the result of evidence-based policies implemented by the service branches following a period characterized by a surge, particularly among recruits, in the incidence of exertional hyponatremia. The Army’s policy, TRADOC Regulation 350-29, was developed to ensure heat illness protocols were more specific and scientifically grounded.¹⁹ This policy, reflecting the latest medical knowledge and lessons about exertional illnesses, established a more effective system for managing heat illness and led to more scientific hydration and work protocols, more precise field diagnosis, improved individual risk assessment, and enhanced leader confidence. The Army protocol combines scientific risk management using Wet Bulb Globe Temperature, strict regulations like fluid intake limits, and targeted education to empower leaders and individual soldiers to prevent the condition. Further investigation and monitoring are needed to enhance effective management of exertional hyponatremia within the Air Force, the only service branch without a recent decline in hyponatremia incidence. The Air Force uses its own heat safety manual, DAFMAN 48-151,²⁰ which is based on the same scientific principles as the Army’s TRADOC 350-2919 but is adapted for its specific operational environment.

The high rates of hyponatremia in 2 seemingly low-risk professional categories, health care and pilots and air crew, may stem not from routine operational duties but instead from unique, high-stress training regimens. Notably, motor transport occupations had 0 cases, underscoring that risk is most concentrated in prolonged, individual physical exertion rather than duties centered on vehicle-based operations.

The surge in hyponatremia incidence among ACSMs ages 30-39 years highlights the need for continuous monitoring and investigation into military-specific circumstances.²¹ Aging is a known risk factor for hyponatremia, and this sudden spike in a typically lower-risk group suggests a possible link to a specific event, such as a unit deployment to a hot environment or a new high-intensity training program for mid-level officers. The fact that the significant decline in the hyponatremia IR among female service members from 2023 to 2025 demonstrated distinct fluctuations suggests an opportunity for in-depth investigation. Published studies present conflicting results on the association between sex and hyponatremia,^16,17,21-24 and sustained monitoring among ACSMs could help clarify the influence of biological sex while improving prevention of exertional hyponatremia.

Proper hydration strategies and effective collaborative management, guided by current policy, are crucial for preventing exertional hyponatremia (Table 3). To reduce risk of exertional hyponatremia, service members of all ranks should be cognizant of mitigation measures such as fluid and electrolyte replacement guidelines, identification of high-risk individuals, and the importance of vigilance during associated activities.¹⁹ Prevention strategies for exertional hyponatremia, developed for the unique physical demands and environmental exposures of military personnel, should be applied universally to all service members. To resolve scientific ambiguities and protect the health of all service members, collection of detailed data on all cases of exertional hyponatremia is crucial, to inform future analysis and more accurately identify trends and risk factors.

References

Carter R. Exertional heat illness and hyponatremia: an epidemiological prospective. Curr Sports Med Rep. 2008;7(4):s20-s27. doi:10.1249/jsr.0b013e31817f38ff
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Armed Forces Health Surveillance Division. Exertional hyponatremia among active component members of the U.S. Armed Forces, 2008–2023. MSMR. 2024;31(4):15-19.
Lebus DK, Casazza GA, Hoffman MD, Van Loan MD. Can changes in body mass and total body water accurately predict hyponatremia after a 161-km running race? Clin J Sport Med. 2010;20(3):193-199. doi:10.1097/jsm.0b013e3181da53ea
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Oh RC, Malave B, Chaltry JD. Collapse in the heat–from overhydration to the emergency room: three cases of exercise-associated hyponatremia associated with exertional heat illness. Mil Med. 2018;183(3-4):e225-e228. doi:10.1093/milmed/usx105
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Jonas C, Arnold M. Exercise-associated hyponatremia: updated guidelines from the Wilderness Medical Society. AFP. 2021;103(4):252-253. Accessed Mar. 24, 2025. https://www.aafp.org/pubs/afp/issues/2021/0215/p252.html
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Chalela R, González-García JG, Chillarón JJ, et al. Impact of hyponatremia on mortality and morbidity in patients with COPD exacerbations. Respir Med. 2016;117:237-242. doi:10.1016/j.rmed.2016.05.003
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Acknowledgment

The editors thank Thomas Wilkerson for analysis of the data presented in this report.

Disclaimers

The editors disclose use of an artificial intelligence (AI) language model in the preparation of this report. Assistance was provided by Gemini Enterprise, a large language model from Google, specifically optimized for Department of War mission support within an Impact Level 5 (IL5) environment. This AI application was used to assist with initial drafts of the discussion, to refine prose for clarity. MSMR editors directed all AI review and analysis, with subsequent editorial staff review and final edits. The editors assert full responsibility for the accuracy and integrity of the final content.

Update: Malaria among members of the U.S. Armed Forces, 2025

Fri, 01 May 2026 00:00:00 Z

Abstract

Malaria infection remains a potential health threat to U.S. service members located in or near endemic areas due to duty assignments, participation in contingency operations, or personal travel. This report summarizes findings from surveillance of malaria infections among U.S. service members in 2025 and analyzes trends for a 10-year period, from 2016 through 2025. In 2025, 36 cases of malaria were diagnosed among U.S. service members, representing a 12.5% increase from 32 cases reported in 2024. The majority of malaria cases occurred in service members who were male (94.4%), in the active component (80.6%), and serving in the Army (63.9%). Africa was the leading region of acquisition (n=14), primarily for P. falciparum infections. A significant 2025 finding is a shift in the predominant species to P. vivax, which accounted for 41.7% (n=15) of all cases, a notable increase from 10% of all cases in 2024. Most P. vivax cases (80.0%) were acquired in Korea. Seasonality of infection remained consistent, with 72.1% of cases diagnosed May through October. These findings underscore the critical need for continuous surveillance, strict command emphasis on personal protective measures, and region-specific prevention strategies to protect the health of the force and maintain military readiness.

What are the new findings?

Findings from 2025 indicate a 12.5% increase in malaria cases among U.S. service members compared to 2024, with a notable increase of new P. vivax cases. This change was driven almost entirely by P. vivax infections acquired in Korea, while Africa remained the principal source for P. falciparum cases.

What is the impact on readiness and force health protection?

The rise of P. vivax from Korea along with persistent P. falciparum infection from Africa not only directly affect force health protection but demonstrate a dynamic, regionally specific threat that requires specialized prevention strategies to maintain military readiness.

Background

Malaria has long posed a significant risk to U.S. military service members and operations.¹ Before World War II, the disease was endemic across the southern U.S., prompting the 1942 establishment of the Office of Malaria Control in War Areas—an organization that would later become the Centers for Disease Control and Prevention—to mitigate vector-borne diseases around military installations.² While this campaign was successful in the elimination of malaria as a public health threat to the U.S. by 1949, the disease remains a persistent risk to the operational readiness of U.S. service members when deployed to endemic tropical and subtropical regions.^3-5

The risk to military personnel is heightened by operational realities, the emergence of drug-resistant parasites, and inconsistent adherence to preventive measures such as chemoprophylaxis and personal protective equipment.^6-9 Travel to malaria-endemic regions, especially for foreign-born personnel visiting their countries of origin, also presents a significant medical concern.^10-11 Studies have shown a significantly higher incidence of malaria in service members and their families with connections to malaria-endemic countries, particularly those from sub-Saharan Africa. This increased risk persists despite universal health coverage and access to pre-travel medical care for this specific population.¹¹ Most human malaria cases are caused by 4 Plasmodium species—P. falciparum, P. vivax, P. malariae, and P. ovale—with P. falciparum and P. vivax the most significant. P. falciparum, found predominantly in Africa, is the most dangerous species, accounting for over 90% of malaria-related deaths,12 while P. vivax has the widest geographic distribution, with a high prevalence in Southeast Asia, the Western Pacific, and the Americas.¹³ These 2 species, P. falciparum and P. vivax, have distinct epidemiological profiles. A critical difference is the ability of P. vivax to cause relapses weeks or even months after initial infection,¹⁴ which occurs because the parasite can remain in the liver as hypnozoites, allowing dormant endemicity during the colder, mosquito-free seasons and extending its geographic range into temperate zones, such as the Korean peninsula.¹⁵

MSMR has published regular updates on malaria’s impact on service members since 1999. Current surveillance efforts include the differentiation of malaria types, such as the more lethal P. falciparum and relapsing P. vivax. This sustained surveillance provides critical data to inform force health protection strategy, and this update continues that mission by describing malaria’s epidemiological patterns among U.S. Armed Forces from 2016 through 2025.

Methods

The surveillance population for this report includes service members of the U.S. Army, Navy, Air Force, Marine Corps, Space Force, and Coast Guard. The surveillance period was January 1, 2016 through December 31, 2025. Records from the Defense Medical Surveillance System (DMSS) were searched to identify qualifying evidence of a malaria diagnosis from reportable medical events (RMEs), hospitalizations, outpatient encounters (in military and non-military facilities), and laboratory results from military facilities.

Case definition criteria for malaria included either 1) an RME record of confirmed malaria, 2) a hospitalization record with a primary diagnosis of malaria, 3) a hospitalization record with a non-primary diagnosis of malaria due to a specific Plasmodium species, 4) a hospitalization record with a non-primary diagnosis of malaria plus a diagnosis of anemia, thrombocytopenia, and related conditions, or malaria-complicating pregnancy in any diagnostic position, 5) a hospitalization record with a non-primary diagnosis of malaria plus diagnoses of signs or symptoms consistent with malaria in each diagnostic position preceding malaria, or 6) a positive malaria antigen test plus an outpatient record with a diagnosis of malaria in any diagnostic position within 30 days of the specimen collection date.¹⁶ The relevant International Classification of Diseases, 9th and 10th revisions (ICD-9/ICD-10) codes used to identify cases are shown in Table 1.

This analysis restricted each service member to 1 episode of malaria per 365-day period. When multiple records documented a single episode, the date of the earliest record was considered the date of clinical onset. Records within 30 days of the clinical onset date were reviewed for evidence of a Plasmodium species.

Presumed locations of malaria acquisition were estimated with a hierarchical algorithm: 1) cases diagnosed in a malaria-endemic country were considered acquired in that country, 2) RMEs that listed exposures to malaria-endemic locations were considered acquired in those locations, 3) RMEs not listing exposures to malaria-endemic locations but reported from installations in malaria-endemic locations were considered acquired in those locations, 4) cases diagnosed among service members during or within 30 days of deployment or assignment to a malaria-endemic country were considered acquired in that country, and 5) cases diagnosed among service members deployed or assigned to a malaria-endemic country within 2 years before diagnosis were considered acquired in those countries. All remaining cases were considered to have acquired malaria in unknown locations.

Results

In 2025, a total of 36 U.S. service members were diagnosed with, or reported to have, malaria (Table 2). The annual total for 2025 represents a 12.5% increase in malaria cases from the 32 cases reported in 2024 (Figure 1). Twenty-eight (77.8%) of the 36 cases in 2025 were identified from RME records. The remaining 8 cases were identified through additional case definition criteria: 5 cases from hospitalization records with a defining diagnosis of malaria in the primary diagnostic position, 2 cases from hospitalization records with a case defining diagnosis of malaria in a non-primary diagnostic position due to a specific Plasmodium species or additional diagnoses for malaria-related conditions, and 1 case from a U.S. Department of War laboratory report of a positive malaria antigen test plus 1 outpatient medical encounter for a case-defining diagnosis of malaria in any diagnostic position within 30 days of the specimen collection date (data not shown).

As in previous years, the majority of U.S. military members diagnosed with malaria in 2025 were men (94.4%), members of the active component (80.6%), and in the Army (63.9%). No cases were reported in the Space Force or Coast Guard. Non-Hispanic Black service members and individuals ages 20-24 years accounted for the most cases of malaria (44.4% and 30.6%, respectively) (Table 2).

Examination of the 28 malaria case records reported as RMEs in 2025 revealed that 5 of the case exposures were classified as deployment-related, 5 as duty-related (but not deployment-related), 10 were non-deployment and non-duty related, while 8 cases were missing exposure classification. Six of the 10 cases classified as non-deployment and non-duty related were documented as acquired in Africa (data not shown).

During the 2016-2025 surveillance period, malaria cases acquired in Africa (n=169, 44.5%) and other or unspecified locations (n=88, 23.2%) accounted for the largest numbers, followed by Korea (n=65, 17.1%), Afghanistan (n=56, 14.7%), and South and Central America (n=2, 0.5%) (Figure 2). Africa consistently reported the highest numbers of malaria cases throughout the period. Cases in Afghanistan peaked to 21 in 2018, thereafter declining to 0 cases during last 3 years of the surveillance period. Malaria cases were diagnosed or reported in 2025 from 21 different medical facilities: 14 facilities in the U.S., 3 facilities in the Republic of (South) Korea, and 1 facility each in Germany, Africa, and Japan, as well as 1 TRICARE Prime remote location (Table 3).

Most U.S. service member malaria cases in 2025 were caused by P. vivax (n=15, 41.7%). Twelve of those 15 P. vivax cases were acquired in Korea. The remaining cases were attributed to P. falciparum (n=14, 38.9%) and other or unspecified types of malaria (n=7, 19.4%). Most cases acquired in Africa (n=14) were caused by P. falciparum (n=10, 71.4%) (Figure 3). The 14 malaria cases acquired in Africa were associated with several countries, including Djibouti (n=3), Ghana (n=3), Cameroon (n=2), Nigeria (n=2), Sierra Leone (n=1), Guinea (n=1), and Tanzania (n=1); 1 case was associated with an unknown African location (data not shown).

From 2016 to 2025, malaria caused by P. falciparum accounted for the greatest number of cases (183, 48.2%) followed by other or unspecified species (n=99, 26.1%), and P. vivax (n=98, 25.8%). Over the 10-year surveillance period, most malaria cases (n=274/380, 72.1%) were diagnosed or reported during the 6 months from the Northern Hemisphere middle of spring through the middle of autumn (i.e., May–October) (Figure 4). The proportions of malaria cases diagnosed or reported May–October varied by region of acquisition: Afghanistan (n=48/56, 85.7%,), Korea (n=58/65, 89.2%), Africa (n=117/169, 69.2%), and South and Central America (n=1/2, 50.0%) (data not shown).

Discussion

The number of malaria cases among U.S. service members saw a modest increase in 2025, rising by 12.5% from the previous year. While the total number of cases remains relatively low, these malaria data reveal several key trends and a notable shift in the dominant parasite species, underscoring the persistent threat of malaria to military personnel operating globally. Consistent with historical trends, the demographic profile of malaria cases in 2025 comprised predominantly young, male soldiers from the active component.^3-5 The majority (77.8%) of cases were identified through routine RMEs, with the remainder captured through hospitalization and laboratory records, highlighting the importance of a multi-faceted surveillance strategy to ensure comprehensive case identification.

Geographically, Africa continues to be a primary region of acquisition for malaria infections, a consistent trend over the last decade.³ The majority of cases acquired in Africa were caused by P. falciparum, the most severe form of the parasite. Cases acquired in Africa were traced to at least 7 different countries, reflecting the widespread risk across the continent.

Perhaps the most significant finding from the 2025 surveillance data is the dramatic shift in the causative species. Nearly half of all cases were attributed to P. vivax, a stark contrast to 2024, when P. falciparum accounted for over half of cases—and P. vivax only 10%. This change is almost entirely driven by cases acquired in Korea, which accounted for 80% of P. vivax infections in 2025. This finding emphasizes the geographically distinct epidemiology of malaria and the specific risks associated with different operational theaters. This risk has long been documented since the Korean War, however, among U.S. and Korean Forces near the Demilitarized Zone.¹⁷

The seasonal pattern of malaria diagnoses remains consistent with previous findings, providing predictable opportunity for targeted force health protection measures. Over the 10-year surveillance period, a significant majority (72.1%) of cases were diagnosed May–October, coinciding with the warmer, wetter months that favor mosquito vector activity.¹⁸ This trend was particularly pronounced for cases acquired in Korea (89.2%), aligning with the established transmission season for P. vivax in temperate zones and reinforcing the need for heightened awareness and preventative measures during these months for personnel in those regions. Vector surveillance programs have shown a correlation between the number of Anopheles species positive for P. vivax sporozoites with the number of malaria cases and exposure of soldiers from the Republic of Korea soldiers from May through October.¹⁹ Even in Africa, where transmission can occur throughout the year,^18,20 nearly 70% of cases were reported during this same period, underscoring its importance as a peak transmission season globally.

Limitations to this report should be considered when interpreting these findings. Malaria case reporting, especially for reserve components and non-deployment exposures, is likely incomplete, contributing to under-estimation of rates; some cases treated in deployed or non-U.S. military medical facilities may not have been reported or otherwise ascertained at the time of analysis. Malaria diagnoses documented only in outpatient settings without confirmatory testing and not reported as RMEs were not included in this report. Geographic location of malaria acquisition was estimated from reported information, with some cases reporting exposures in multiple malaria-endemic areas and others with no relevant exposure information. Personal travel or deployment to malaria-endemic countries was not documented unless specified in RMEs. Limited information on species types in RME records emphasizes the need for more complete attention to documentation of reportable conditions.

These findings emphasize the need for continuous surveillance, regionally specific prevention strategies, and robust diagnostic capabilities to protect U.S. service members from this persistent infectious disease. While the overall burden of malaria within the U.S. military is not significant, 2025 data illustrate a dynamic and evolving threat, with the continued prevalence of P. falciparum in Africa posing a significant risk for severe disease and the sharp increase in P. vivax from Korea demonstrating a different, but equally important, regional challenge.

References

Shanks GD. Post-infection symptoms in U.S. soldiers with malaria during the Second World War: major limitation to return to duty. MSMR. 2026;33(2):8-10. Accessed Apr. 28, 2026. https://www.health.mil/news/articles/2026/02/01/msmr-malaria-post-infection-world-war-ii
U.S. Centers for Disease Control and Prevention. Elimination of Malaria in the United States (1947–1951). U.S. Dept. of Health and Human Services. Jul. 23, 2018. Accessed Sep. 5, 2025. https://stacks.cdc.gov/view/cdc/100616
Armed Forces Health Surveillance Division. Malaria among members of the U.S. Armed Forces, 2024. MSMR. 2025;32(4):22-28. Accessed Apr. 28, 2026. https://www.health.mil/news/articles/2025/04/01/msmr-malaria-2024-update
Armed Forces Health Surveillance Division. Malaria among members of the U.S. Armed Forces, 2023. MSMR. 2024;31(5):31-36. Accessed Apr. 28, 2026. https://www.health.mil/news/articles/2024/05/01/msmr-malaria-update
Armed Forces Health Surveillance Division. Malaria in service members and beneficiaries, U.S. Armed Forces, 2018–2022. MSMR. 2023;30(3):2-9. Accessed Apr. 28, 2026. https://www.health.mil/reference-center/reports/2023/03/01/msmr-volume-30-issue-3-march-2023
Saunders DL, Garges E, Manning JE, et al. Safety, tolerability and compliance with long-term antimalarial chemoprophylaxis in American soldiers in Afghanistan. Am J Trop Med Hyg. 2015;93(3):584-590. doi:10.4269/ajtmh.15-0245
Wallace MR, Sharp TW, Smoak B, et al. Malaria among United States troops in Somalia. Am J Med. 1996;(1):49-55. doi:10.1016/s0002-9343(96)90011-x
National Academies of Sciences, Engineering, and Medicine, Savitz DA, Styka AN, eds. Assessment of Long-Term Health Effects of Antimalarial Drugs When Used for Prophylaxis. The National Academies Press;2020. Accessed Mar. 31, 2026. doi:10.17226/25688
Miles D. Deployed servicemembers step up anti-malarial protections. American Forces Press Service. Apr. 9, 2004. Accessed Mar. 31, 2026. https://www.af.mil/news/article-display/article/137192/deployed-servicemembers-step-up-anti-malarial-protections
Rudiger CL, Nowak G. Malaria trends in the Navy and Marine Corps, 2005–2013. Mil Med. 2016;181(5):488-493. doi:10.7205/milmedd-15-00174
Helfrich AM, Lu D, Grance M, Chu X, Hickey PW. Malaria incidence in US military families is related to service member’s birthplace. Open Forum Infect Dis. 2025;12(8). doi:10.1093/ofid/ofaf479
U.S. Centers for Disease Control and Prevention. Malaria. DPDx-Laboratory Identification of Parasites of Public Health Concern. U.S. Dept. of Health and Human Services. Updated Dec. 13, 2024. Accessed Mar. 31, 2026. https://www.cdc.gov/dpdx/malaria/index.html
World Health Organization. World Malaria Report 2024: Addressing Inequity in the Global Malaria Response. World Health Organization;2024. Accessed Mar. 31, 2026. https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2024
Howes RE, Battle KE, Mendis KN, et al. Global epidemiology of Plasmodium vivax. Am J Trop Med Hyg. 2016;95(suppl 6):15-34. doi:10.4269/ajtmh.16-0141
Gething PW, Elyazar IR, Moyes, et al. A long neglected world malaria map: Plasmodium vivax endemicity in 2010. PLoS Negl Trop Dis. 2012;6(9):e1814. doi:10.1371/journal.pntd.0001814
Armed Forces Health Surveillance Division. Malaria Surveillance Case Definition. Updated Feb. 2019. Accessed Mar. 31, 2026. Defense Health Agency, U.S. Dept. of War. https://health.mil/reference-center/publications/2014/12/01/malaria
Feighner BH, Park S, Novakoski WL, Kelsey LL, Strickman D. Re-emergence of Plasmodium vivax malaria in the Republic of Korea. Emerg Infect Dis. 1998;4(2):295-297. doi:10.3201/eid0402.980219
U.S. Centers for Disease Control and Prevention. Where Malaria Occurs. U.S. Dept. of Health and Human Services. Mar. 18, 2024. Accessed Apr. 8, 2026. https://www.cdc.gov/malaria/data-research/index.html
Chang KS, Yoo DH, Ju YR, et al. Distribution of malaria vectors and incidence of vivax malaria at Korean army installations near the demilitarized zone, Republic of Korea. Malaria J. 2016;15:259. doi:10.1186/s12936-016-1301-y
Yamba EI, Fink AH, Kingsley B, et al. Climate drivers of malaria transmission seasonality and their relative importance in Sub-Saharan Africa. GeoHealth. 2023;7(2). doi:10.1029/2022gh000698

Acknowledgments

The editors thank the Navy and Marine Corps Public Health Center–Portsmouth, for providing laboratory data for this analysis. The editors thank Gi-Taik Oh for analysis of the data presented in this report.

Disclaimers

Update: Exertional rhabdomyolysis among U.S. active component service members, 2021–2025

Fri, 01 May 2026 00:00:00 Z

Abstract

Exertional rhabdomyolysis is a pathologic muscle breakdown associated with strenuous physical activity. A largely preventable condition, it persists as an occupational hazard of military training and operations, especially in high heat environments among individuals pushing their endurance limits. A total of 521 cases of exertional rhabdomyolysis were identified in the U.S. Armed Forces in 2025, corresponding to a crude incidence rate of 39.7 cases per 100,000 person-years. This rate is consistent with 2023-2024 levels but remains higher than rates from 2021-2022. The percentage of inpatient cases rose to a 5-year peak of 46.3% in 2025, however, a 21.6% relative increase from the low of 38.0% recorded in 2022. In 2025, the Air Force demonstrated the most significant rate increase, 60.0%, followed by the Army, with a 16.4% increase. In contrast, the Marine Corps and Navy showed rate decreases of 32.4% and 34.8%, respectively, when compared to 2024. The Coast Guard’s annual case numbers remained low, ranging 4–6 cases throughout the 5-year surveillance period. Consistent with prior reports, subgroup-specific crude rates in 2025 were highest among men, those younger than age 20 years, non-Hispanic Black service members, Marine Corps or Army members, and those in combat-specific or ‘other’ military occupations. In 2025, recruit trainees continued to experience the highest rates of exertional rhabdomyolysis, with a rate more than 6 times greater than officers and enlisted members.

What are the new findings?

In 2025, a total of 521 cases of exertional rhabdomyolysis resulted in a crude incidence rate of 39.7 cases per 100,000 person-years, consistent with 2023-2024 levels, yet higher than 2021-2022 levels. Meanwhile, in 2025 the proportion of cases requiring inpatient admission climbed to a 5-year peak of 46.3%, marking at 21.6% increase from the 2022 low. The period from 2024 to 2025 manifested opposite trends, with rates increasing in the Army and the Air Force while decreasing in the Marine Corps and the Navy. The Air Force showed the largest increase, with incidence rates 60% higher from the previous year.

What is the impact on readiness and force health protection?

Exertional rhabdomyolysis is a serious threat to military members that can limit their service effectiveness and potentially predispose them to serious injury. Risk of developing exertional rhabdomyolysis can be reduced by awareness of environmental conditions, cognizance of troop fitness levels, emphasis on graded pre-conditioning prior to more strenuous training, adherence to recommended work and rest ratios with appropriate hydration schedules, especially in hot, humid weather, and prompt recognition of symptoms by commanders.

Background

Initiation of a high-intensity physical activity at unaccustomed intensity or duration, particularly under heat stress, increases the risk of exertional rhabdomyolysis.¹ A potentially serious condition, exertional rhabdomyolysis requires vigilance for early diagnosis and aggressive treatment to prevent serious consequences. Rhabdomyolysis is characterized by the breakdown of skeletal muscle cells and leakage of intracellular contents (e.g., myoglobin, sarcoplasmic proteins, electrolytes) into the extracellular fluid and the circulatory system. Myoglobin is toxic to the tubular cells of the kidney and can lead to renal failure.

Rhabdomyolysis severity ranges from asymptomatic or mild elevation of serum muscle enzyme levels to life-threatening emergencies, such as electrolyte imbalances, acute kidney failure, disseminated intravascular coagulation, compartment syndrome, cardiac arrhythmia, or liver dysfunction.^1-4 The characteristic triad of rhabdomyolysis symptoms are muscle pain, weakness, and red- to brown-colored urine, due to high levels of myoglobin, although over half of patients do not have all of these specific symptoms.⁵

The standard diagnostic criteria for exertional rhabdomyolysis are muscle pain, weakness, and dark urine, or elevated serum creatine kinase (CK) levels, indicating myonecrosis, usually defined as a CK level of at least 5 times the upper limit of normal, following recent exercise.^2,3,6

Exertional rhabdomyolysis is most commonly identified among new recruits at recruit training and combat installations, during the first 90 days of basic training,^7,8 but it can be observed in athletes accustomed to intense training, particularly when they extend themselves to the maximal limits of their physical endurance.⁹ The condition occurs most frequently from mid-spring through early autumn at installations that support basic combat, recruit training, or major Army or Marine Corps combat units. Recruits can be exposed to environments requiring acclimatization to high heat or humidity in hotter months, while soldiers and marines in combat units often perform rigorous unit physical training, personal fitness training, and field training exercises regardless of weather conditions. A history of heat illness or prior heat stroke has also been described as significant risk factors for service members who sustained rhabdomyolysis,^8,10 revealing the potential for co-morbid conditions.

MSMR annually summarizes the numbers, rates, trends, risk factors, and locations of exertional heat injury occurrences including exertional rhabdomyolysis. This report includes updated surveillance data from 2021 through 2025. Additional information about the definition, causes, and prevention of exertional rhabdomyolysis can be found in previous issues of MSMR.⁷

Methods

The surveillance period ranged from January 2021 through December 2025 and included all individuals who served in the active component of the U.S. Army, Navy, Air Force, Marine Corps, Space Force, or Coast Guard. Due to small numbers, Space Force members were included in the Air Force population. All data used to determine incident exertional rhabdomyolysis diagnoses were derived from records routinely maintained in the Defense Medical Surveillance System (DMSS). These records document both ambulatory encounters and hospitalizations of active component members of the U.S. Armed Forces in fixed military and civilian (if reimbursed through the Military Health System) hospitals and clinics worldwide.

A case of exertional rhabdomyolysis was defined as an individual with International Classification of Diseases, 9th or 10th revision (ICD-9/ICD-10) diagnostic codes in any position indicating a hospitalization (i.e., inpatient) or outpatient medical encounter record with either “rhabdomyolysis” or “myoglobinuria” listed, plus a diagnosis in any position of 1 of either “volume depletion (dehydration),” “effects of heat and light,” “effects of thirst (deprivation of water),” “exhaustion due to exposure,” or “exhaustion due to excessive exertion (overexertion)” (Table 1).¹¹ Each individual could be considered an incident case of exertional rhabdomyolysis only once per calendar year.

Cases of rhabdomyolysis associated with trauma, intoxications, and adverse drug reactions were excluded.¹² For health surveillance purposes, recruit trainees were identified as active component members assigned to service-specific training locations during coincident, service-specific basic training periods. Recruit trainees were considered a separate enlisted service member category in exertional rhabdomyolysis summaries by military grade.

The surveillance data reflect the most current information available at the time of analysis. Case counts are finalized over subsequent reporting cycles to incorporate data from all treatment facilities, which may be subject to routine reporting delays. Consequently, case numbers and incidence rates for a given year may be retrospectively adjusted in future reports.

Results

In 2025, a total of 521 cases of rhabdomyolysis likely associated with physical exertion or heat stress (i.e., exertional rhabdomyolysis) were identified, corresponding to a crude incidence rate (IR) of 39.7 cases per 100,000 person-years (p-yrs) (Table 2). This rate is consistent with 2023-2024 levels and remains higher than rates observed in 2021-2022 (Figure 1). Consistent with prior annual reports, crude IRs remained highest among men, those younger than age 20 years, Marine Corps or Army members, non-Hispanic Black service members, and those in combat-specific, motor transport, and ‘other’ occupations (Table 2). During the surveillance period, 2021-2025, approximately three-quarters (75.9%) of cases occurred during the warmer months (April–September) (Figure 3).

Recruit trainees continued to have the highest rates of exertional rhabdomyolysis in 2025, at a rate of over 6 times greater than officers and enlisted members. The percentage of rhabdomyolysis cases hospitalized in 2025 was 46.3% (n=241), a 13.7% increase from 2024. Proportions of hospitalized or inpatient cases were lowest in 2022, at 38.0% (Figure 1).

Over the 5-year surveillance period, the highest case counts and IRs of exertional rhabdomyolysis were observed in the Marine Corps (n=736, IR 85.9 per 100,000 p-yrs) and the Army (n=1,371, IR 60.4 per 100,000 p-yrs) (data not shown). The rates for the Air Force (n=268, IR 16.6 per 100,000 p-yrs), Navy (n=196, IR 11.8 per 100,000 p-yrs), and Coast Guard (n=24, IR 12.1 per 100,000 p-yrs) were substantially lower. The Coast Guard’s annual case count remained consistently low, ranging 4–6. No cases were identified among Space Force members.

When comparing 2025 rates to 2024, the IR of the Air Force increased by 60.0%, while the IR for the Army rose by 16.4% (Figure 2). In contrast, rates decreased in the Marine Corps and the Navy, by 32.4% and 34.8%, respectively. The 2025 IR of exertional rhabdomyolysis in the Navy was the lowest, at 8.7 cases per 100,000 p-yrs.

From 2024 to 2025, the IR among Hispanic service members decreased by 30.4% (from 42.4 to 29.5 cases per 100,000 p-yrs). Non-Hispanic Black service member rates were more than double those of other racial and ethnic groups, rising by 13.4% from 2024 (65.7 per 100,000 p-yrs) to 2025 (74.5 per 100,000 p-yrs). The rate remained stable for non-Hispanic White service members (34.3 in 2024 vs. 34.6 cases in 2025) (data not shown).

During the 5-year surveillance period, 22 installations diagnosed at least 20 cases each; when combined, these installations diagnosed 68.1% of all cases (Table 3). Of those 22 installations, 7 support recruit or basic combat training centers: Marine Corps Recruit Depot (MCRD) Parris Island/Beaufort, South Carolina; Fort Benning, Georgia; Joint Base San Antonio-Lackland, Texas; Fort Leonard Wood, Missouri; MCRD San Diego, California; Fort Jackson, South Carolina; and Fort Sill, Oklahoma; while 11 installations support large combat troop populations: Fort Bragg, North Carolina; Fort Campbell, Kentucky; Marine Corps Base (MCB) Camp Lejeune, North Carolina; Fort Shafter, Hawai’i; Fort Hood, Texas; MCB Camp Pendleton, California; Fort Bliss, Texas; Fort Polk, Louisiana; Fort Stewart, Georgia; Fort Carson, Colorado; and Marine Corps Air Ground Combat Center (MCAGCC) Twentynine Palms, California. From 2021 through 2025, Fort Bragg, MCRD Parris Island/Beaufort, and Fort Benning together accounted for over 28.3% of all cases (Table 3).

Discussion

The crude IR of exertional rhabdomyolysis in 2025 was 39.7 cases per 100,000 p-yrs, consistent with 2023 and 2024 rates, remaining elevated in relation to 2021-2022 levels. While provisional data in last year’s report suggested a decline in 2024,¹³ more complete data (as of March 2026), show that the rate was consistent with those of 2023 and 2025. Overall, these data indicate a stable but elevated incidence during the latter 3 years (2023-2025) of the 5-year surveillance period compared to the initial 2 years (2021-2022).

Following last year’s reporting period, divergent trends emerged, however, among the service branches: Rates increased in the Army and the Air Force and decreased in the Marine Corps and the Navy. The Air Force demonstrated the most substantial rate increase for exertional rhabdomyolysis incidence in 2025, at 60.0%, the highest among all service branches, after showing the largest decline in 2024.¹² In contrast, the Marine Corps and the Navy saw comparable rate decreases in 2025, of 32.4% and 34.8%, respectively, when compared to 2024 data, with the Navy recording its lowest rate in 2025.

In 2025 the percentage of cases hospitalized rose to a 5-year peak of 46.3%, a 21.6% increase from the lowest percentage, in 2022. This trend may reflect a rebound to pre-pandemic levels or increased clinical vigilance for risk mitigation that possibly led to a higher proportion of cases managed in an inpatient setting. This trend coincides with the release of the updated Clinical Practice Guideline for the Management of Exertional Rhabdomyolysis in Warfighters⁶ in September 2025, which emphasizes standardized risk stratification and clearer admission criteria, focusing on early recognition of symptoms and CK thresholds.

The IR for non-Hispanic Black service members increased by 13.3% in 2025, while rates declined for Hispanic service members and remained stable for non-Hispanic White members. The persistently high IRs of exertional rhabdomyolysis among non-Hispanic Black service members (approximately twice the rates in other racial and ethnic groups), has been attributed, in part, to increased risk of exertional rhabdomyolysis among individuals with Sickle Cell Trait (SCT),^13-15 for which the carrier frequency is approximated at 1 in 13 for non-Hispanic Black individuals in the U.S.^16-20 Despite the 2023 TRADOC Regulation²¹ formally recognizing SCT as a risk factor, with updated screening, early recognition, and prevention of exercise collapse associated with sickle cell trait (ECAST) strategies, the disparity has not improved. Further analysis into additional physiological, social, or environmental risk factors may be warranted.

The findings of this report should be interpreted with consideration of its limitations. A diagnosis of rhabdomyolysis alone does not indicate cause. Ascertaining the probable causes of exertional rhabdomyolysis cases was attempted by using a combination of ICD-9/ICD-10 diagnostic codes related to rhabdomyolysis with additional codes indicating effects of exertion, heat, or dehydration. Other ICD-9/ICD-10 codes were used to exclude cases of rhabdomyolysis that may have been secondary from trauma, intoxication, or adverse drug reactions. Recruit trainees were identified using an algorithm based on entry date into service, age, rank, location, and time in service, which was only an approximation and likely resulted in some misclassification of recruit training status.

The surveillance data for 2025 should be interpreted with caution due to reporting lags and updates of annual case counts, as data feeds are continuously uploaded and as data matures. Nevertheless, the diverging trends among the service branches from 2024 to 2025 suggest varied and possibly unequal implementation of preventive strategies within the services. These data also present an opportunity for further comparative analysis of contributing factors among the service branches. Service-specific public health and medical assets are encouraged to conduct targeted studies to identify and assess individual, operational, and environmental factors contributing to risk of exertional rhabdomyolysis, and evaluate the effectiveness of any preventive or mitigative interventions implemented.

Management after treatment for exertional rhabdomyolysis, including the decision to return to physical activity and duty, is a persistent challenge for military members and athletes.^22,23 The updated Clinical Practice Guideline provides a detailed and structured framework for return-to-duty decisions, allowing lower-risk individuals to follow a standard, criterion-based progression model, while higher-risk cases require more cautious and individualized plans, managed by specialists. The most severe consequences of exertional rhabdomyolysis are preventable with effective mitigation measures accompanied by heightened suspicion of probability when environmental conditions favor muscular injury. Commanders and supervisors at all levels should ensure that guidelines for heat illness prevention are consistently implemented, maintain vigilance for early signs of exertional heat injury, and intervene aggressively when exertional rhabdomyolysis is suspected.

References

Rawson ES, Clarkson PM, Tarnopolsky MA. Perspectives on exertional rhabdomyolysis. Sports Med. 2017;47(suppl 1):33-49. doi:10.1007/s40279-017-0689-z
Zutt R, van der Kooi AJ, Linthorst GE, Wanders RJ, de Visser M. Rhabdomyolysis: review of the literature. Neuromuscul Disord. 2014;24(8):651-659. doi:10.1016/j.nmd.2014.05.005
Chavez L, Leon M, Einav S, Varon J. Beyond muscle destruction: a systematic review of rhabdomyolysis for clinical practice. Crit Care. 2016;20:135. doi:10.1186/s13054-016-1314-5
Bosch X, Poch E, Grau JM. Rhabdomyolysis and acute kidney injury. NEJM. 2009;361(1):62-72. doi:10.1056/nejmra0801327
Gabow PA, Kaehny WD, Kelleher SP. The spectrum of rhabdomyolysis. Medicine (Baltimore). 1982;61(3):141-152. doi:10.1097/00005792-198205000-00002
Clinical Practice Guideline for the Management of Exertional Rhabdomyolysis in Warfighters. Uniformed Services University, Consortium for Health and Military Performance;2025. Accessed Mar 27, 2026. https://www.hprc-online.org/resources-partners/whec/clinical-care/clinical-practice
Armed Forces Health Surveillance Branch. Exertional rhabdomyolysis among active component members, U.S. Armed Forces, 2014–2018. MSMR. 2019;26(4):21-26. Accessed Mar 27, 2026. https://www.health.mil/reference-center/reports/2019/04/01/medical-surveillance-monthly-report-volume-26-number-4
Hill OT, Scofield DE, Usedom J, et al. Risk factors for rhabdomyolysis in the U.S. Army. Mil Med. 2017;182(7):e1836-e1841. doi:10.7205/milmedd-16-00076
Raleigh MF, Barrett JP, Jones BD, et al. A cluster of exertional rhabdomyolysis cases in a ROTC program engaged in an extreme exercise program. Mil Med. 2018;183(suppl 1):516-521. doi:10.1093/milmed/usx159
Hill OT, Wahi MM, Carter R, et al. Rhabdomyolysis in the U.S. active duty Army, 2004–2006. Med Sci Sports Exerc. 2012;44(3):442-449. doi:10.1249/mss.0b013e3182312745
Armed Forces Health Surveillance Division. Exertional rhabdomyolysis among active component members of the U.S. Armed Forces, 2020–2024. MSMR. 2025;32(6):11-16. Accessed Apr. 14, 2026. https://www.health.mil/news/articles/2025/06/01/msmr-rhabdomyolysis-2025
Armed Forces Health Surveillance Branch. Surveillance Case Definition: Exertional Rhabdomyolysis. Defense Health Agency, U.S. Dept. of War. Accessed Mar. 27, 2026. https://www.health.mil/reference-center/publications/2017/03/01/rhabdomyolysis-exertional
Makaryus JN, Catanzaro JN, Katona KC. Exertional rhabdomyolysis and renal failure in patients with sickle cell trait: is it time to change our approach? Hematology. 2007;12(4):349-352. doi:10.1080/10245330701255254
Ferster K, Eichner ER. Exertional sickling deaths in Army recruits with sickle cell trait. Mil Med. 2012;177(1):56-59. doi:10.7205/milmedd-11-00106
Naik RP, Smith-Whitley K, Hassell KL, et al. Clinical outcomes associated with sickle cell trait: a systematic review. Ann Intern Med. 2018;169(9):619-627. doi:10.7326/m18-1161
U.S. Centers for Disease Control and Prevention. Data and Statistics on Sickle Cell Disease. U.S. Dept. of Health and Human Services. Accessed May 15, 2025. https://www.cdc.gov/sicklecell/data/?cdc_aaref_val=https://www.cdc.gov/ncbddd/sicklecell/data.html
Nelson DA, Deuster PA, Carter R, et al. Sickle cell trait, rhabdomyolysis, and mortality among U.S. Army soldiers. NEJM. 2016;375(5):435-442. doi:10.1056/nejmoa1516257
Webber BJ, Nye NS, Covey CJ, et al. Exertional rhabdomyolysis and sickle cell trait status in the U.S. Air Force, January 2009–December 2018. MSMR. 2021;28(1):15-19. Accessed Jun. 16, 2025. https://www.health.mil/reference-center/reports/2021/01/01/medical-surveillance-monthly-report-volume-28-number-01
Eichner ER. The vagaries of exertional rhabdomyolysis. Cur Sports Med Rep. 2021;20(5):229-230. doi:10.1249/jsr.0000000000000833
Webber BJ, Nye, NS, Harmon, KG, et al. Exertional rhabdomyolysis, sickle cell trait, and “military misdirection”. Cur Sports Med Rep. 2021;20(10):562-563. doi:10.1249/jsr.0000000000000897
Training and Doctrine Command, Department of the Army. Training Prevention of Heat and Cold Casualties. TRADOC Regulation 350-29. U.S. Dept. of War;2023. Accessed Jun. 16, 2025. https://adminpubs.tradoc.army.mil/regulations/tr350-29.pdf
O’Connor FG, Brennan FH, Campbell W, Heled Y, Deuster P. Return to physical activity after exertional rhabdomyolysis. Curr Sports Med Rep. 2008;7(6):328-331. doi:10.1249/jsr.0b013e31818f0317
Atias D, Druyan A, Heled Y. Recurrent exertional rhabdomyolysis: coincidence, syndrome, or acquired myopathy? Curr Sports Med Rep. 2013;12(6):365-369. doi:10.1249/jsr.0000000000000007

Acknowledgment

The editors thank Erika Dreyer for analysis of the data presented in this report.

Disclaimers

Annual review of reportable medical events at Military Health System facilities, January 1, 2025–December 31, 2025

Fri, 01 May 2026 00:00:00 Z

This month’s edition of the MSMR Reportable Medical Events at Military Health System (MHS) facilities report provides an overview of annual data for 2025 for active component service members (ACSMs) and MHS beneficiaries. Reportable Medical Events (RMEs) are reported in the Disease Reporting System internet (DRSi) by health care providers and public health officials throughout the MHS for monitoring, controlling, and preventing the occurrence and spread of diseases of public health interest. These reports are validated by the Defense Health Agency–Public Health (DHA-PH).

The DRSi collects reports on over 70 different RMEs, including infectious and non-infectious conditions, outbreak reports, sexually transmitted infection (STI) risk surveys, and tuberculosis contact investigation reports. A complete list of RMEs is available in the 2022 Armed Forces Reportable Medical Events Guidelines and Case Definitions.¹ Data presented in this report are considered provisional and do not represent conclusive evidence until case reports are fully validated.

Top 5 RMEs in 2025, by MMWR Week, for ACSMs and MHS beneficiaries

The top 5 RMEs reported to DRSi in 2025 for ACSMs included chlamydia, gonorrhea, norovirus, heat illness, and syphilis (Figure 1), unchanged from 2024.

For MHS beneficiaries, the top 5 RMEs reported included chlamydia, norovirus, influenza-associated hospitalization, gonorrhea, and campylobacteriosis (Figure 2), similar to reporting in 2024, with the exception of influenza-associated hospitalization.

Ratios of RMEs for 2025 compared to 2024 for ACSMs and MHS beneficiaries

The current ratio data are based on incidence counts comparing year 2025 to 2024; low numbers for many conditions limit data interpretation and are not included in the figures. Conditions with less than 10 medical event reports (MERs) per year and syphilis were excluded from the ratio comparisons; syphilis and hepatitis B cases were excluded due to changes in case validation processes implemented throughout 2024. Ratios presented in Figure 3 and Figure 4 include any RMEs that had, at minimum, a 30% increase or decrease in MERs in 2025 respective to MERs in 2024.

For ACSMs, the total number of MERs submitted to DRSi in 2025 decreased by 4.8% compared to 2024. Cases of cold weather injuries and cyclosporiasis had the most prominent increases in 2025 compared to 2024, with increases of 155% and 100%, respectively. Increases of case counts in 2025 were also recorded for spotted fever rickettsiosis (+82%), norovirus (+63%), and malaria (+52%). There were decreases in 2 RMEs in 2025 versus 2024 for ACSMs: for coccidioidomycosis (-55%) and E. coli, Shiga toxin-producing (-31%) (Figure 3).

For MHS beneficiaries, the total number of MERs submitted to DRSi in 2025 decreased by 12.2% compared to 2024. MHS beneficiaries saw the most prominent increases for cases of influenza-associated hospitalizations and spotted fever rickettsiosis in 2025, with increases of 65% and 50%, respectively. Reports of norovirus also increased among MHS beneficiaries in 2025 versus 2024 (+37%). MHS beneficiaries saw the most significant decrease in cases of COVID-19-associated hospitalization and death (-65%) and shigellosis (-57%) compared to 2024. Decreases were also seen in reports E. coli, Shiga toxin-producing (-49%), varicella (-32%), and hepatitis C, acute and chronic (-30%) (Figure 4).

Discussion

Like the DHA-PH, the U.S. Centers for Disease Control and Prevention (CDC) reported similar trends for the increased influenza-associated hospitalizations in 2025 compared to 2024. The CDC classified the 2024-2025 influenza season as high severity, with the highest estimates of influenza-related illnesses and medical visits since the 2010-2011 influenza season.² Hospitalization rates were equivalent in 2024-2025 to those during the 2017-2018 season, the last high-severity influenza season.² Additionally, the CDC reported decreases in COVID-19 hospitalization rates from the 2023-2024 season to the 2024-2025 season, with a similar trend in the MHS.³

For questions about this report, please contact the Disease Epidemiology Branch at the Defense Centers for Public Health–Aberdeen. Email: dha.apg.pub-health-a.mbx.disease-epidemiologyprogram13@health.mil

References

Armed Forces Health Surveillance Division. Armed Forces Reportable Medical Events. Defense Health Agency, U.S. Dept. of War. Accessed Apr. 1, 2026. https://health.mil/reference-center/publications/2022/11/01/armed-forces-reportable-medical-events-guidelines
U.S. Centers for Disease Control and Prevention. 2024–2025 Influenza Season Summary: Severity, Disease Burden, and Burden Prevented. U.S. Dept. of Health and Human Services. Accessed Apr. 1, 2026. https://www.cdc.gov/flu-burden/php/data-vis-vac/2024-2025-prevented.html
U.S. Centers for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19) Hospitalization Surveillance Network (COVID-NET). U.S. Dept. of Health and Human Services. Accessed Apr. 2, 2026. https://www.cdc.gov/covid/php/covid-net/index.html

New digital card connects service members to brain health resources in the Military Health System

Wed, 15 Apr 2026 00:00:00 Z

The Military Health System today announced a new digital resource card to support service members who may have experienced a concussive event. The card offers fast and reliable access to trusted brain health tools and services through a convenient, scannable QR code linked directly to the resources page within the MHS Warfighter Brain Health Hub.

The digital card is available as a downloadable PDF. It serves as a centralized guide, connecting users to information on recognizing concussion symptoms, seeking medical care, accessing recovery resources, and supporting long-term cognitive health.

Developed with the unique needs of military personnel in mind, the card is print-friendly, easily sharable, and links to curated resources about warfighter brain health.

“This initiative reflects a broader commitment to advancing brain health across the force and ensures service members have the knowledge and tools necessary to respond effectively to potential injuries,” said Keith Bass, assistant secretary of war for health affairs. “By connecting users directly to the Warfighter Brain Health Hub, the digital card supports faster intervention, informed decision-making, and improved health outcomes.”

Key features of the digital card include:

QR code-enabled instant access to https://health.mil/Military-Health-Topics/Warfighter-Brain-Health/Resources
Quick symptom recognition to identify concussion indicators
Access to care resource links, including a military hospital and clinic locator, Defense Intrepid Network listing and support services
Guidance for next steps, including when and how to seek medical evaluation
Connection to educational materials on recovery, rest, and return-to-duty considerations

The inclusion of a QR code supports rapid information-sharing across units, briefings, and training materials. Leaders and health care providers can download and share the digital version of the card or incorporate the QR code into posters, handouts, badge inserts, and digital communications — helping reinforce awareness and encourage timely care-seeking behavior.

“Early recognition and proper care after a concussive event are critical to protecting brain health and maintaining operational readiness,” added Kathy Lee, director of Warfighter Brain Health Policy, Office of the Assistant Secretary of War for Health Affairs. “By linking this digital card to the resources page of the Warfighter Brain Health Hub, we’re directing service members where to find immediate access to authoritative, up-to-date information and support resources.”

To access the digital card, visit the Warfighter Brain Health Hub.

‘It has been a life saver’: Department of War civilians in Japan discuss health care pilot program

Wed, 01 Apr 2026 00:00:00 Z

The Office of the Assistant Secretary of War for Health Affairs hosted a virtual information session March 10, 2026, to gather feedback on the effectiveness of the Pilot Health Insurance Enhancement for Department of War Civilian Employees In Japan.

Launched Jan. 1, 2025, the program provides supplemental health services for approximately 11,000 DOW civilian employees in Japan — addressing challenges when seeking medical care including language barriers and high up-front costs.

Susan Orsega, deputy assistant secretary of war for health services policy and oversight, highlighted that “participant insights and feedback play a critical role in shaping the future of the program, which has already helped many individuals get the care they need.”

Since its launch, the program has facilitated over 1,400 appointments and prevented over $1 million in upfront costs to patients. In collaboration with International SOS, or ISOS, the pilot program will continue through Sept. 29, 2026.

How the health insurance enhancement works

To start the information session, officials presented an overview of the pilot program’s key services:

Health Expert assistance through ISOS in finding providers, overcoming language barriers, and understanding local procedures
Streamlined cashless/claimless billing and reimbursement services through ISOS
Interpreter support

Current pilot eligibility is extended to DOW civilian employees with assignments in Japan enrolled in participating Federal Employee Health Benefit program plans, which include:

Federal Blue Cross Blue Shield
Foreign Service Benefit Plan
Government Employee Health Association
Hawaii Medical Service Association
Mail Handlers Benefit Plan
Nonappropriated Funds employees are eligible if enrolled in Aetna International

The pilot program’s services are at no cost to eligible employees, while standard copayments and cost-shares still apply per individual FEHB programs.

To use the pilot program, employees must make an initial 15- to 20-minute setup call with ISOS, which one beneficiary described in the town hall as “extremely easy.”

Translation and interpretation

Officials at the town hall identified language as a common barrier to health care for employees in Japan. The program provides a call center staffed with bilingual professionals, including nurses, to assist with:

Appointment scheduling
Arranging payment guarantees
Answering program questions, or providing guidance for navigating Japanese health care

In-person interpreter services are also available in some cases. On the topic of language barriers, one beneficiary in attendance shared they “couldn’t have navigated Japan’s health care without this pilot program.”

Officials also outlined specific best practices when navigating Japan’s health care system to foster a positive DOW employee reputation among Japanese providers, including being:

Proactive in calling ISOS as soon as care needs are identified
Courteous of provider’s time by cancelling appointments well in advance
Open-minded to the specialties offered in Japan and work with ISOS to find the best course of action
Understanding of limitations of provider availability in Japan

Streamlined billing assistance

Officials detailed how, during a call with ISOS, they will assist in:

Verifying coverage through a benefit review
Coordinating with insurance carriers for direct billing to prevent upfront costs wherever possible
In cases where direct billing isn’t possible, ISOS can help streamline reimbursements

Direct billing is powered by agreements with a large network of medical providers in Japan, allowing ISOS to issue guarantees of payment to providers — preventing patients from having to pay any upfront costs. Under the agreement, FEHB plans reimburse ISOS, and patients direct their regular copayment and shared costs to ISOS.

Looking ahead to future access to health care

Officials report strong advocacy for the program from users and ISOS has 98.7% success in collecting co-pays from patients after FEHB carriers process the directly billed claims.

Ultimately, the pilot program continues to gather feedback from users and evaluate its impact. The Undersecretary of War for Personnel and Readiness will review the program’s outcomes and determine how to sustain, scale, or adapt it prior to the program’s contracted conclusion in September 2026.

Many participants in the town hall voiced enthusiasm for the program’s continuation, with one beneficiary stating, “I very much appreciate the program and we’re hoping for an expansion. It has been a life saver.”

Head and neck cancer among U.S. active component service members, 2010–2024

Wed, 01 Apr 2026 00:00:00 Z

Abstract

This study utilized de-identified surveillance data to estimate the incidence of head and neck cancer among active component service members (Army, Navy, Air Force, Marine Corps, Coast Guard) from 2010 through 2024. This report updates the June 2021 MSMR analysis of oral and pharyngeal cancers (2007-2019) by expanding the case definition to include all head and neck cancers and extending the surveillance period through 2024. There were 549 cases of head and neck cancer diagnosed in the active component military during the 15-year period of analysis. The Army had the highest 15-year incidence rate (3.3 per 100,000 person-years) compared to the Navy (2.6 per 100,000), Air Force (2.6 per 100,000), Coast Guard (2.0 per 100,000), and Marine Corps (1.3 per 100,000). Service members ages 40 years and older had the highest overall incidence rate (12.3 per 100,000), which was 3.3 times the next highest rate observed among those ages 35-39 years. The 15-year male incidence rate (2.9 per 100,000) was greater than that among females (1.7 per 100,000). The parotid gland was the most common site of diagnosis, comprising 14.8% of cases.

What are the new findings?

From 2010 through 2024, 549 cases of head and neck cancer were diagnosed among U.S. active component service members. The branch of service, sex, and age group with the highest incidence rates were the Army, males, and those ages 40 years and older. The most common site was the parotid gland.

What is the impact on readiness and force health protection?

This report provides the most current head and neck cancer incidence data for active component service members from 2010 through 2024; it establishes baseline rates for monitoring of future trends and highlights specific high-risk populations (e.g., men, Army personnel, service members ages 40 years and older). Although head and neck cancer is the seventh most prevalent cancer worldwide, its incidence among active component service members is seldom reported. Head and neck cancer is often not diagnosed until it has metastasized. Significant physical limitations (e.g., difficulty chewing, speaking, and swallowing) and psychosocial effects (e.g., anxiety, depression, social isolation), compromising service member readiness, can accompany this type of cancer.

Background

Head and neck cancer (HNC), the seventh most prevalent cancer worldwide,^1,2 is a collective term for cancers originating in the head and neck region including the lip, oral cavity, nasal cavity, paranasal sinuses, salivary glands, pharynx, and larynx. In 2022, there were over 940,000 new cases of HNC and 480,000 fatalities globally.^1,2 Signs and symptoms may vary depending upon where specifically within the head and neck region the cancer originated. Cancer originating in the oral cavity may result in sores that do not heal, growth or swelling causing dentures to fit poorly, and unusual bleeding or pain.^3,4 Alternatively, cancer that originates in the pharynx may cause difficulty with essential functions including breathing, speaking, and swallowing food.^3,4 Various factors dictate the course of treatment including the location and stage of the tumor, as well as patient-specific factors, such as age and health history. Considering the complexity of this type of cancer and the numerous subsites, a multidisciplinary approach to treatment is required.⁵

Survival rates, like course of treatment, are strongly influenced by the location and stage at diagnosis. According to the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program, the overall 5-year relative survival rate of oral cavity and pharynx cancer is 69.5%.⁶ When considering the stage at diagnosis, the 5-year survival rates for localized (i.e., confined to primary site), regional (i.e., spread to regional lymph nodes), and distant (i.e., metastasized) oral cavity and pharynx cancer are 88.4%, 69.4%, and 36.9%, respectively.⁶ Laryngeal cancer survival rates, however, are lower compared to oral cavity and pharynx cancer.⁷ The overall 5-year relative survival rate is 62.1%, and the 5-year survival rates for localized, regional, and distant laryngeal cancer are 79.3%, 49%, and 35.2%, respectively.⁷

Major risk factors of HNC include alcohol and tobacco use, betel nut chewing, and infection with human papillomavirus (HPV).⁸ HPV infections are usually asymptomatic and resolve naturally. However, long-lasting infections with high-risk strains of HPV (16 and 18) can cause various types of cancer (e.g., anal, cervical, oropharyngeal, penile, vaginal, vulvar).^9,10 Remarkably, about 70% of oropharyngeal squamous cell carcinoma cases in the U.S. are attributed to HPV.^8,10,11

Additional risk factors of HNC include genetics, Epstein-Barr virus infection, radiation therapy, exposure to occupational or environmental carcinogens, and immunodeficiency.⁸ HNC is more likely to be diagnosed in those older than age 55 years and is more than twice as common in men compared to women.^3,12,13 Moreover, a recent study determined that men are far more susceptible to HNC compared to women, regardless of tobacco and alcohol use.¹³

Numerous studies have explored the incidence of HNC among military veterans; the same cannot be said about active component service members (ACSMs). This is unsurprising, as the active component military population is considered a generally young population, and HNC is significantly more common among those older than age 55 years. A recent study investigated the incidence of the 16 most common cancers among ACSMs¹⁴; HNC was not included in that list. This type of cancer represents a small component of the overall cancer burden among this population and, consequently, may not often be explored. However, HNC is usually not diagnosed until it has metastasized. HNC can be accompanied by significant physical limitations (e.g., difficulty chewing, speaking, and swallowing) and psychosocial effects (e.g., anxiety, depression, social isolation), compromising service member readiness. Investigating its incidence among ACSMs is important and relevant. This report serves as an update to the June 2021 MSMR analysis on the incidence of oral cavity and pharynx cancers among ACSMs from 2007 through 2019, expanding the case definition to include all HNCs and extending the surveillance period to 2010-2024.¹⁵

Methods

This investigation was completed at the Tri-Service Center for Oral Health Studies (TSCOHS), a center of the Uniformed Services University (USU), the nation’s federal health professions academy. The USU Human Research Protection Program approved this study, as protocol DBS.2025.827. Data were obtained from the Armed Forces Health Surveillance Division (AFHSD), the central epidemiological health resource for the U.S. military.

The surveillance population included ACSMs of the U.S. Army, Navy, Air Force, Marine Corps, and Coast Guard diagnosed with HNC from the January 1, 2010 through December 31, 2024. Cases were identified by International Classification of Diseases, 9th and 10th revisions (ICD-9/ICD-10), codes for malignant neoplasms of the lip, oral cavity, pharynx, nasal cavity, larynx, and sinuses (Table 1). This report builds upon a prior 2021 analysis¹⁵ of the same population (with the addition of the Coast Guard) from 2007 to 2019 but uses a broader case definition. The prior study was restricted to malignant neoplasms of the lip, oral cavity, and pharynx.

For surveillance purposes, a case of HNC was defined by AFHSD as either 1 hospitalization with a case defining diagnosis of HNC (Table 1) in the first diagnostic position; or 1 hospitalization with a procedure code indicating radiotherapy, chemotherapy, or immunotherapy treatment in the first diagnostic position and a case-defining diagnosis of HNC (Table 1) in the second diagnostic position; or 3 or more outpatient medical encounters within a 90-day period, with a case-defining HNC diagnosis (Table 1) in the first or second diagnostic position. For those who met the case definition, the incidence date was the date of the first qualifying hospitalization or outpatient medical encounter with a case-defining HNC diagnosis. An individual was considered an incident case once per lifetime. Additional variables evaluated included branch of service, sex, year of diagnosis, and age at diagnosis. Annual incidence rates (IRs) were calculated for each service branch, sex, and age group, by dividing the number of cases in that subgroup by the number of ACSMs reported in the Defense Medical Epidemiology Database (DMED) for that subgroup and year. The ACSM population counts reported by DMED are the cumulative person years (p-yrs) contributed during the calendar year of interest for the population substratum.

Results

From 2010 through 2024, 549 cases of HNC were diagnosed among U.S. ACSMs. Yearly IRs ranged from 1.9 to 3.6 cases per 100,000 p-yrs (Figure 1) with an overall IR of 2.7 cases per 100,000 p-yrs. The number of HNC cases among male service members (n=492) was far greater than that among female service members (n=57) (Table 2). Likewise, the overall IR among men (2.9 per 100,000 p-yrs) exceeded that of women (1.7 per 100,000 p-yrs). As of 2024, male service members accounted for 82.2% of the active component and an even greater proportion (89.6%) of all identified HNC cases during the study period (Table 2).

The largest number (31) of cases occurred among service members who were age 43 years at diagnosis. When evaluated by age group, service members ages 40 years and older accounted for the largest proportion (47.5%) of HNC cases, with the largest overall IR (12.3 per 100,000 p-yrs) compared to the remaining younger age groups (Table 2). As of 2024, service members ages 40 years and older comprised only 10.5% of the active component; the majority (60%) of the active component is younger than age 30 years.

The Army had the largest number of HNC cases (n=247), followed by the Navy (n=128), Air Force (n=127), Marine Corps (n=35), and finally Coast Guard (n=12) (Table 2). The Army accounts for the greatest proportion (34.1% in 2024) of the active component and had an even greater proportion of all cases (45%). Likewise, the Coast Guard constitutes the smallest proportion (3.1% in 2024) of the active component and had the smallest proportion (2.2%) of all cases. The Coast Guard did not have the lowest overall IR, however, which was evidenced by the Marine Corps, with an IR of 1.3 cases per 100,000 p-yrs; the Army had the highest overall IR (3.3 per 100,000 p-yrs) (Table 2).

The 10 most frequent sites diagnosed with HNC are presented in Figure 2. ‘Unspecified’ indicates that the subsite was not documented. For instance, ‘tongue, unspecified’ signifies that the specific location of the tumor on the tongue (e.g., border, dorsal, base) is unknown. The greatest number of cases occurred in the parotid gland (n=81), accounting for 14.8% of all cases during the 15-year surveillance period. However, if combining cases diagnosed in the same primary location, the greatest number of cases (n=94, or 17.1%) occurred on the tongue (tongue, unspecified=57; tongue base=37).

Discussion

This study utilized de-identified surveillance data from AFHSD to estimate the incidence of HNC among ACSMs (Army, Navy, Air Force, Marine Corps, Coast Guard) from 2010 through 2024. This is the first time this group of cancers has been investigated by TSCOHS. These data can help guide military public health policy and future research into specific occupational or lifestyle risk factors within high-risk demographic groups.

In the general population, risk of diagnosis of HNC significantly increases with age; the same can be said for the military. Service members ages 40 years and older comprise the smallest proportion of the active component, yet had the greatest proportion of cases and an IR 3.3 times the next highest IR, which was observed among those ages 35-39 years. Likewise, men in the general population are at a greater risk of developing HNC, which also applies to the military, as male service members had an IR 1.7 times that of female service members.

The 2021 study conducted determined the incidence of oral cavity and pharynx cancer among ACSMs from 2007 through 2019.¹⁵ While the present study expanded the 2021 study to include cancer in all locations considered HNC, in addition to the oral cavity and pharynx, very similar results were found. As with the present study, the 2021 investigation determined that the branch of service, sex, and age group with the highest IRs included the Army, men, and those ages 40 years and older.¹⁵ Furthermore, the most common diagnosed site in both studies was the parotid gland.¹⁵

The difference in IRs among the service branches may be due to the differing age distributions among them, as also suggested in the 2021 study.¹⁵ Service members with the greatest risk of HNC were those ages 40 years and older. The Marine Corps had the lowest overall HNC IR. Likewise, the proportion of service members ages 40 years or older is lowest in the Marine Corps (4.9%). Notably, this proportion is at least 2 times lower than that of any other service branch, ranging from 9.9% in the Air Force to 18.3% in the Coast Guard (DMED).

The small number of cases in this study precluded meaningfully stratified analysis due to limited statistical power to separate true trends from random fluctuations. The reliance on de-identified medical encounter data presented with additional limitations. Cancer diagnoses could not be independently verified, and thus, the results could be subject to misclassification errors leading to either an over- or under-estimation of cases. Individual risk factors could not be linked to diagnoses; differences in known contributing risk factors (e.g., tobacco and alcohol use, HPV infection) may explain the differences in IRs among the service branches. The Army had the highest IR, 2.5 times that of the Marine Corps, which might suggest higher rates of contributing risk factors in the Army. According to the 2018 Health Related Behavior Survey, however, both binge and heavy drinking were the highest among Marine Corps and Navy members.¹⁶ Furthermore, Marine Corps members were more likely to be current cigarette smokers, electronic cigarette smokers, and smokeless tobacco users compared to service members of all other branches.¹⁶

Certain military service members are subject to an added environmental hazard associated with HNC: burn pit exposure. The Department of Veterans Affairs has recognized HNC, in addition to various other cancers, as a “presumptive cancer” related to burn pit exposure among those who served in Iraq, Afghanistan, or certain other areas.¹⁷ As such, these individuals may be eligible for disability compensation.¹⁷

Risk of developing HNC is related to prolonged, repeated exposure to the known risk factors; this type of cancer can take years, even decades, to develop.^3,4,8-12 Considering that HNC diagnosis may not occur until long after a service member has left service, numerous studies have evaluated HNC among the veteran population. Unfortunately, the prevalence of HNC among veterans is nearly twice that of the general population.^18-21 Factors believed to contribute to this are the high rates of tobacco and alcohol use among this population, as well as low rates of HPV vaccination,^22-26 which may not have been an option for some veterans, depending upon their ages.

HNC represents a small portion of the overall disease burden among ACSMs compared to other cancers such as breast cancer or melanoma.¹⁴ The significance of such a debilitating, albeit uncommon, disease should not be discounted, however. Early detection is paramount to improving prognosis, as is educating patients regarding the signs, symptoms, and risk factors for HNC.^27,28 Military dentists contribute significantly to early detection. ACSMs are required to have a yearly dental examination which provides dentists with the opportunity to not only educate ACSMs about HNC but evaluate them for suspicious lesions in the head and neck region. This is consistent with the American Dental Association’s “Early Detection and Prevention of Oral and Oropharyngeal Cancer” policy, which recommends cancer prevention education and a routine visual and tactile examination for all patients.²⁷ Nevertheless, given the implications of early detection, regular self-examinations for signs of HNC are equally vital.

References

Bray F, Laversanne M, Sung H, et al. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2024;74(3):229-263. doi:10.3322/caac.21834
Sun H, Yu M, An Z, et al. Global burden of head and neck cancer: epidemiological transitions, inequities, and projections to 2050. Front Oncol. 2025;15:1665019. doi:10.3389/fonc.2025.1665019
National Cancer Institute. Head and Neck Cancers. National Institutes of Health. May 2021. Accessed Jan. 21, 2026. https://www.cancer.gov/types/head-and-neck/head-neck-fact-sheet#r31
U.S. Centers for Disease Control and Prevention. Head and Neck Cancers Basics. Jun. 2025. Accessed Jan. 21, 2026. https://www.cdc.gov/head-neck-cancer/about/index.html#:~:text=A%20white%20or%20red%20sore,Problems%20with%20dentures
Anderson G, Ebadi M, Vo K, et al. An updated review on head and neck cancer treatment with radiation therapy. Cancers. 2021;13(19):4912. doi:10.3390/cancers13194912
National Cancer Institute. Surveillance, Epidemiology, and End Results Program. Cancer Stat Facts: Oral Cavity and Pharynx Cancer. National Institutes of Health. Accessed Jan. 21, 2026. https://seer.cancer.gov/statfacts/html/oralcav.html
National Cancer Institute. Surveillance, Epidemiology, and End Results Program. Cancer Stat Facts: Laryngeal Cancer. National Institutes of Health. Accessed Jan. 21, 2026. https://seer.cancer.gov/statfacts/html/laryn.html
Barsouk A, Aluru JS, Rawla P, et al. Epidemiology, risk factors, and prevention of head and neck squamous cell carcinoma. Med Sci. 2023;11(2):42. doi:10.3390/medsci11020042
Brianti P, De Flammineis E, Mercuri SR. Review of HPV-related diseases and cancers. New Microbiol. 2017;40(2):80-85. Accessed Mar. 16, 2026. https://pubmed.ncbi.nlm.nih.gov/28368072
National Cancer Institute. HPV and Oral Cancer. National Institutes of Health. May 2025. Accessed Jan. 21, 2026. https://www.cancer.gov/about-cancer/causes-prevention/risk/infectious-agents/hpv-and-cancer#:~:text=HPV%2Drelated%20research-,What%20is%20HPV%20(human%20papillomavirus)?,controlled%20by%20your%20immune%20system
U.S. Centers for Disease Control and Prevention. HPV and Oropharyngeal Cancer. U.S. Dept. of Health and Human Services. Sep. 2024. Accessed Jan. 21, 2026. https://www.cdc.gov/cancer/hpv/oropharyngeal-cancer.html
Siegel RL, Miller KD, Fuchs HE, et al. Cancer statistics, 2021. CA Cancer J Clin. 2021;71(1):7-33. doi:10.3322/caac.21654
Park JO, Nam IC, Kim CS, et al. Sex differences in the prevalence of head and neck cancers: a 10-year follow-up study of 10 million healthy people. Cancers. 2022;14(10):2521. doi:10.3390/cancers14102521
Lovejoy LA, Shriver CD, Ellsworth RE. Cancer incidence and etiology in the active-duty population of U.S. military. Mil Med. 2024; 23;189(1-2):e58-e65. doi:10.1093/milmed/usac297
Goodwin CE. Oral cavity and pharynx cancers, active component, U.S. armed forces, 2007–2019. MSMR. 2021;28(7):11-14. Accessed Mar. 16, 2026. https://www.health.mil/reference-center/reports/2021/07/01/medical-surveillance-monthly-report-volume-28-number-07
Meadows S, Engel C, Collins R, et al. 2018 Department of Defense Health Related Behaviors Survey: Active Component. RAND Corporation;2021. https://www.rand.org/pubs/research_reports/RR4222.html
U.S. Department of Veterans Affairs. Presumptive Cancers Related to Burn Pit Exposure. Apr. 2025. Accessed Mar. 16, 2026. https://www.va.gov/resources/presumptive-cancers-related-to-burn-pit-exposure/#brain-head-neck-and-nervous-sy
Zayan KL, McCoy JL, Boudreaux-Kelly MY, et al. Geographic and socioeconomic landscape of veterans with head and neck cancer. Head Neck. 2025;47(10):2845-2855. doi:10.1002/hed.28209
Jackson JM, Wu EL, Brody L, et al. Predictors of survival in veterans with head and neck cancer treated surgically. J Laparoendosc Adv Surg Tech A. 2023;33(6):566-569. doi:10.1089/lap.2023.0057
Zevallos J, Kramer J, Sandulache V, et al. National trends in oropharyngeal cancer incidence and survival within the Veterans Health Care System. Head Neck. 2021;43(1):108-115. doi:10.1002/hed.26465
Patil RD, Meinzen-Derr JK, Hendricks BL, et al. Improving access and timeliness of care for veterans with head and neck squamous cell carcinoma: a multidisciplinary team’s approach. Laryngoscope. 2016;126(3):627-631. doi:10.1002/lary.25528
Odani S, Agaku IT, Graffunder CM, et al. Tobacco product use among military veterans: United States, 2010–2015. MMWR Morb Mortal Wkly Rep. 2018;67:7-12. doi:10.15585/mmwr.mm6701a2
Davis JP, Livingston WS, Landis RK, Ramchand R. Alcohol use disorder among U.S. veterans: veterans’ issues in focus. Expert Insights. RAND Corporation. Jun. 10, 2025. Accessed Mar. 16, 2026. https://www.rand.org/pubs/perspectives/pea1363-14.html
Teeters JB, Lancaster CL, Brown DG, et al. Substance use disorders in military veterans: prevalence and treatment challenges. Subst Abuse Rehabil. 2017;(8):69-77. doi:10.2147/sar.s116720
U.S. Centers for Disease Control and Prevention. Military Service Members and Veterans. Tips from Former Smokers. U.S. Dept. of Health and Human Services. Feb. 2024. Accessed Mar. 16, 2026. https://www.cdc.gov/tobacco/campaign/tips/groups/military.html
Dubiel LJ, Vinekar KS, Than CT, et al. Human papillomavirus vaccination rates among U.S. military veteran females and males and non-veterans in the national health interview survey. Mil Med. 2025;190(5-6):e1152-e1158. doi:10.1093/milmed/usae490
American Dental Association. Current Policies Adopted 1954–2016: Early Detection and Prevention of Oral and Oropharyngeal Cancer (Trans.2019:277). 2019. Accessed Mar. 17, 2026. http://www.ada.org/en/member-center/leadershipgovernance//-/media/project/ada-organization/ada/ada-org/files/advocacy/current_policies.pdf
National Institutes of Health, National Institute of Dental and Craniofacial Research. Detecting Oral Cancer: A Guide for Healthcare Professionals. Aug. 2020. Accessed Mar. 16, 2026. https://www.nidcr.nih.gov/health-info/publications/detecting-oral-cancer-guide-healthcare-professionals

Author’s Affiliation

Tri-Service Center for Oral Health Studies, Uniformed Services University, Joint Base San Antonio, Fort Sam Houston, TX

Disclaimers

The opinions and assertions expressed herein are those of the author and do not reflect the official policy or position of the Uniformed Services University of the Health Sciences, Department of the Army, Department of War, or U.S. Government.

LTC Goodwin is a military service member. This work was prepared as part of official duties. Title 17, U.S. Code Section 105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S. Code Section 101 defines a U.S. Government work as a work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties.

References to non-Federal entities or products do not constitute nor imply a U.S. Department of War or Uniformed Services University of the Health Sciences endorsement.

The author does not have a financial interest in any commercial product, service, or organization providing financial support for this research. The author declares no conflict of interest.

Brief report: Incidence of oropharyngeal cancer among U.S. active component service members, 2005–2024

Wed, 01 Apr 2026 00:00:00 Z

Oropharyngeal cancer develops in the oropharynx, which is comprised of the soft palate, side and back walls of the throat, tonsils, and back of the tongue.¹ Oropharyngeal cancer is distinguished from cancers arising in the oral cavity and pharynx, otherwise known as head and neck cancers, which include the lip, salivary glands, mouth and gums, and entire throat (or pharynx) and tongue.²

Oropharyngeal cancer comprises 2 distinct cancers, HPV-positive and HPV-negative types, with different risk factors and age distributions. It is estimated that 60-70% of oropharyngeal cancers in the U.S. are due to infections with high-risk types of human papillomavirus (HPV), with smoking and heavy alcohol use acting as important risk factors for HPV-negative types.³ HPV-positive cancers tend to be diagnosed in people younger than age 50 years, whereas HPV-negative types tend to be diagnosed among older individuals.⁴ In addition, HPV-positive oropharyngeal cancers tend to have better prognosis and respond better to treatment.⁵ The first HPV vaccine became available in the U.S. for women ages 9-26 years in 2006.⁶ A bivalent vaccine became available in 2009, and a 9-valent vaccine became available for women and men in 2014.⁶

Despite the availability of the HPV vaccine over the past 20 years, data published in 2025 indicate that incidence of oropharyngeal cancer in the U.S. increased slightly between 2006 and 2022, primarily among men and older individuals.⁷ A previous study by the Murtha Cancer Center compared incidence rates of oral cavity and oropharyngeal cancers among active duty service men and men in the U.S. population between 1990 and 2013.⁸ That study found that active duty incidence rates of oropharyngeal cancer were higher than U.S. population rates among non-Hispanic White individuals (IRR 1.19, 95% CI 1.01, 1.39) and men ages 40-59 years (IRR 1.18, 95% CI 1.00, 1.39), and rates increased for both populations over time.⁸

Continued oropharyngeal cancer surveillance among U.S. service members was identified as a gap by the DHA public health cancer surveillance community of interest, and a new surveillance case definition for oropharyngeal cancer was created. This analysis represents the first use of the new case definition. This study aimed to examine the trend in annual incidence of oropharyngeal cancer among U.S. active component service members (ACSMs), a comparatively young and healthy population, from 2005 through 2024.

Methods

Data for this study were obtained from the Defense Medical Surveillance System (DMSS), a relational database that documents military and medical data for U.S. service members throughout their military careers. Incident cases of oropharyngeal cancer were identified by the presence of a single inpatient encounter with a qualifying diagnosis in the first diagnostic position (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM]: 141.0, 141.5, 141.6, 141.8 141.9, 145.3-145.5, 146.0-146.2, 146.3-146.9, 149.0, 149.1, 149.8; International Classification of Diseases, 10th Revision, Clinical Modification [ICD-10-CM]: C01, C02.4, C02.8, C02.9, C05.1, C05.2, C05.8, C05.9, C09.0, C09.1, C09.9, C09.9, C10*, C14.0, C14.2, C14.8), or a ‘V’- or ‘Z’- treatment code (ICD-10-CM: Z51.0, Z51.1, Z51.11, Z51.12; ICD-9-CM: V58.0, V58.1, V58.11, V58.12) in the first diagnostic position and a qualifying diagnosis in the second diagnostic position, or with 3 or more outpatient encounters in a 90-day period with a qualifying diagnosis in the first or second diagnostic position. An individual was counted as an incident case only once per lifetime. Person-time was counted in years of active component service and was censored at the date of incident diagnosis. Multivariable Poisson regression models were used to calculate adjusted incidence rate ratios for service branch, rank, and military occupation, after controlling for age, sex, and racial and ethnic group.

Results

From 2005 through 2024, 341 new cases of malignant oropharyngeal cancer were diagnosed among U.S. ACSMs, corresponding to an incidence rate (IR) of 1.27 cases per 100,000 person-years (p-yrs) (Table 1). There was no clear increase or decrease in annual incidence observed during the surveillance period (Figure). Instead, IRs fluctuated between a low of 0.79 cases per 100,000 p-yrs in 2023 and high of 1.87 cases per 100,000 p-yrs in 2014. The most common anatomical site of incident diagnosis was the tonsil (n=94, 28%), followed by other and unspecified parts of the tongue (n=85, 25%), oropharynx (n=76, 22%), base of the tongue (n=54, 16%), ill-defined sites of lip, oral cavity and pharynx (n=20, 6%), and soft palate (n=12, 3.5%) (data not shown).

Incidence of oropharyngeal cancer was 6 times higher in male ACSMs compared to female ACSMs, with rates increasing significantly with increasing age (Table 1). Non-Hispanic White ACSMs had the highest rate, compared to the other known racial and ethnic groups. Compared to other service branches, ACSMs in the Marine Corps had the lowest rate, and Army members had the highest rate, which remained true even after adjustment for age, sex, and race and ethnicity (Table 2). Officers had a higher crude incidence compared to enlisted members; however, this was no longer true in the adjusted analysis. Pilots and air crew had the highest crude IRs compared to other occupations, but ACSMs in motor transport occupations had the highest adjusted rates.

Discussion

The demographic and time trends of oropharyngeal cancer incidence among ACSMs observed in this analysis are similar to the findings from a 2021 MSMR report on oral cavity and pharynx cancers, with men and older service members showing higher rates of diagnosis.² Unlike trends observed in the U.S. during a similar period, annual IRs in ACSMs did not increase over time—but there was no obvious decrease. Overall oropharyngeal cancer incidence in the U.S. is not expected to be affected significantly by the HPV vaccine until 2045, as older individuals who did not receive an HPV vaccine will remain at increased risk until then.^6,9

In the U.S., oropharyngeal cancer rates are slightly higher among non-Hispanic White individuals compared to other racial and ethnic groups, which was consistent with this report’s findings among ACSMs.^10,11 One hypothesized reason for this trend includes varying oral sexual behaviors, which are associated with high-risk HPV infection, among different racial and ethnic groups.¹² Other potential hypotheses include birth cohort effects, varied levels of smoking behaviors, as well as socio-economic factors and access to health care.¹² This study did not intend to compare oropharyngeal incidence rates to the U.S. population. It would not be appropriate to use the findings of this study to compare to the U.S. population due to differences in case ascertainment methodology and underlying population differences. Instead, the intent of this study was to evaluate internal trends of oropharyngeal cancer within the active component U.S. military. Limitations of this study included the fact that annual incidence trends could not be evaluated among subgroups by sex or age due to the small number of cases identified during the long surveillance period. In addition, data on risk and protective factors including alcohol use, smoking, and full HPV vaccination history were not available.

Oropharyngeal cancer is rare among ACSMs, likely due to the fact it is a cancer primarily affecting older age groups, with an average age of onset age 64 years.¹³ Because 20% of oropharyngeal cancers are estimated to occur in individuals younger than age 55 years, however, continued surveillance of population cancer rates is recommended to determine the evolving impacts of vaccination and changing lifestyle factors.¹³ Surveillance of cancer trends is necessary for maintaining a fit and medically ready military fighting force, ensuring long-term operational effectiveness, and helping to identify service-related environmental trends or risk factors.

References

National Cancer Institute. Oropharyngeal cancer. NCI Dictionary of Cancer Terms. National Institutes of Health, U.S. Dept. of Health and Human Services. Accessed Nov. 7, 2025. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/oropharyngeal-cancer
Goodwin CE. Oral cavity and pharynx cancers, active component, U.S. Armed Forces, 2007-2019. MSMR. 2021;28(7):11-14. Accessed Mar. 25, 2026. https://www.health.mil/reference-center/reports/2021/07/01/medical-surveillance-monthly-report-volume-28-number-07
U.S. Centers for Disease Control and Prevention. HPV and Oropharyngeal Cancer. U.S. Dept. of Health and Human Services. Accessed Nov. 10, 2025. https://www.cdc.gov/cancer/hpv/oropharyngeal-cancer.html
American Cancer Society. Risk Factors for Oral Cavity and Oropharyngeal Cancers. Cancer.org. 2026. Accessed Jan. 25, 2026. https://www.cancer.org/cancer/types/oral-cavity-and-oropharyngeal-cancer/causes-risks-prevention/risk-factors.html
Lechner M, Liu J, Masterson L, Fenton TR. HPV-associated oropharyngeal cancer: epidemiology, molecular biology and clinical management. Nat Rev Clin Oncol. 2022;19(5):306-327. doi:10.1038/s41571-022-00603-7
Markowitz LE, Gee J, Chesson H, Stokley S. Ten years of human papillomavirus vaccination in the United States. Acad Pediatr. 2018;18(2S):s3-s10. doi:10.1016/j.acap.2017.09.014
Cao C, Lee A, Kang JJ, et al. Updated estimates of patients with oropharyngeal cancer in the US. JAMA Netw Open. 2025;8(10):e2539258. doi:10.1001/jamanetworkopen.2025.39258
Bytnar JA, Shriver CD, Zhu K. Incidence rates of oral cavity and oropharyngeal cancers among men: a comparison of active-duty military and general populations. Eur J Cancer Prev. 2022;31(2):166-171. doi:10.1097/cej.0000000000000698
Zhang Y, Fakhry C, D’Souza G. Projected association of human papillomavirus vaccination with oropharynx cancer incidence in the US, 2020–2045. JAMA Oncol. 2021;7(10):e212907. doi:10.1001/jamaoncol.2021.2907
Damgacioglu H, Sonawane K, Zhu Y, et al. Oropharyngeal cancer incidence and mortality trends in all 50 states in the US, 2001–2017. JAMA Otolaryngol Head Neck Surg. 2022;148(2):155-165. doi:10.1001/jamaoto.2021.3567
Mazul AL, Chidambaram S, Zevallos JP, Massa ST. Disparities in head and neck cancer incidence and trends by race/ethnicity and sex. Head Neck. 2023;45(1):75-84. doi:10.1002/hed.27209
Brawley OW. Oropharyngeal cancer, race, and the human papillomavirus. Cancer Prev Res (Phila). 2009;2(9):769-772. doi:10.1158/1940-6207.capr-09-0150
American Cancer Society. Key Statistics for Oral Cavity and Oropharyngeal Cancers. Cancer. org. 2025. Accessed Nov. 10, 2025. https://www.cancer.org/cancer/types/oral-cavity-and-oropharyngeal-cancer/about/key-statistics.html

Authors’ Affiliation

Epidemiology and Analysis Branch, Armed Forces Health Surveillance Division, Public Health Directorate, Defense Health Agency, Silver Spring, MD: Dr. Stahlman, Ms. Dreyer

Disclaimer

The views expressed in this report reflect the results of research conducted by the authors and do not necessarily reflect the official policy or position of the Defense Health Agency, Department of War, nor the U.S. Government.

Dr. Stahlman is an employee of the U.S. Government. This work was prepared as part of official duties. Title 17, U.S. Code Section 105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S. Code Section 101 defines a U.S. Government work as a work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties.

Distribution of tobacco and nicotine use indicators from the Periodic Health Assessment and medical diagnostic codes among U.S. active component service members, 2023

Wed, 01 Apr 2026 00:00:00 Z

Abstract

Military service members remain a priority population for assessing the prevalence, patterns, and long-term consequences of tobacco and nicotine use. The limitations inherent to documenting use among military service members, however, complicate the design of exposure assessment. This study combined 2 data sources—by aggregating self-reported Periodic Health Assessment (PHA) survey data with International Classification of Diseases, 9th and 10th revisions, Clinical Modification (ICD-9-CM/ICD-10-CM) medical diagnostic codes—to classify nicotine and tobacco use as exposures delineated by recent use or history of any use. The study population included a total of 921,394 U.S. active component service members who completed a PHA in 2023. PHA classification for ‘recent use’ was defined by self-reported use of any tobacco or nicotine product within the past 30 days, whereas ‘history of any use’ included recent users in addition to those who reported cessation of use. The full roster of service members who completed the PHA in 2023 was matched to ambulatory and inpatient medical records within 30 days, before or after, the PHA sample period (December 1, 2022–January 31, 2024) to identify selected ICD-10-CM codes for recent use. Selected diagnostic codes for a ‘history of any use’ were queried for a period of 20 years preceding and 30 days following (January 1, 2004–January 31, 2024) the PHA sample period. Among PHA respondents, 22.0% (n=203,156) self-reported recent nicotine or tobacco use. When aggregating PHA data with recent exposure classified from diagnostic codes, the resulting assessment of recent nicotine or tobacco use increased to 28.7% (n=264,194). Critically, this aggregation identified 61,038 U.S. service members with no evidence of recent use on the PHA but with a concurrent clinical record during the specified matching period. Aggregating data sources for a history of any use only nominally improved the estimate, increasing it from 41.1% (PHA alone) to 43.1%. Agreement between sources was fair for both recent use (κ=0.28) and historical use (κ=0.36). The results of this study indicate that neither self-reported PHA data nor medical diagnostic codes alone provide a complete picture of tobacco and nicotine use among U.S. active component service members.

What are the new findings?

The combination of medical diagnostic codes with self-reported PHA survey responses increases exposure estimates of recent tobacco or nicotine use among U.S. active component service members to 28.7%, in comparison to 22.0% if exclusively assessing recent use from the PHA.

What is the impact on readiness and force health protection?

The integration of multiple data sources may provide a more comprehensive assessment of recent nicotine and tobacco exposure among service members, directly supporting enhanced public health surveillance.

Background

A 2014 Surgeon General’s report highlighted tobacco and nicotine use in the U.S. Armed Forces as a focus of careful study, underscoring a critical need for robust and continuous public health surveillance methods.¹ This need persists today, as the U.S. Surgeon General has identified U.S. military service members as a priority population for developing effective prevention and cessation programs.² T he prevalence of tobacco use remains higher among active duty service members compared to the general U.S. population, compounding the issue of reduced military readiness.³ T he effects on short-term health and operational effectiveness are significant, impairing physical endurance, cognitive function and vision, while also slowing recovery from injury.⁴ Furthermore, smoking degrades readiness by increasing the risk of work absenteeism, respiratory infections, and complications with wound healing.⁴

In the U.S. Department of War (DOW), several data sources are available to assess service members’ tobacco and nicotine use, each characterized by different strengths and limitations. The Health Related Behaviors Survey (HRBS), a DOW flagship survey, in 2018 estimated 37.8% of service members currently used tobacco in some form, such as combustible cigarettes, e-cigarettes, cigars, smokeless tobacco, pipes, or hookahs. Limitations from the latest HRBS publication note that the response rate (9.6%) is considered low for survey research, which can result in a non-representative sample and affect the accuracy of prevalence estimates.⁵ The DOW’s annual Periodic Health Assessment (PHA) offers a more representative sample of service members, as a mandatory annual requirement to assess currency of individual medical readiness.⁶ While survey data from the PHA provide specific, individual exposures by asking about a range of tobacco and nicotine use within the last 30 days, length of use, and past use, the mandated nature of the assessment may lead to under-reporting when compared to the confidential HRBS.⁷

Diagnostic codes from medical records, such as the International Classification of Diseases, 9th and 10th revisions, Clinical Modification (ICD-9-CM/ICD-10-CM) codes, provide an alternate measure. These include codes for current nicotine dependence, tobacco use, and a personal history of nicotine dependence. Use of these diagnostic codes have been shown to substantially under-estimate the prevalence of use, however, when compared to survey data.^8,9 This under-estimation may be influenced by service-branch-specific cultural norms and attitudes towards tobacco use, as well as a potential reluctance among service members to disclose behaviors to health care providers that could be perceived negatively or affect their careers.^10,11

These inherent limitations associated with the documentation of tobacco and nicotine use complicate the design of epidemiological studies, including those measuring prevalence and incidence, monitoring trends, and assessing risk factors for various health outcomes. Furthermore, the longitudinal characterization of use presents methodological challenges, as individuals may initiate, quit, and relapse multiple times throughout their military careers. The primary objective of this study was to evaluate the concordance between 2 distinct data sources—self-reported surveys from the Periodic Health Assessment (PHA) and administrative medical diagnostic codes—to classify all-inclusive categories for tobacco and nicotine use. This study specifically measured and compared the level of agreement of classifications for “recent nicotine or tobacco use” and “history of any nicotine or tobacco use,” to understand the unique contribution of each data source. By characterizing the distribution of data for this complex behavior, these results are intended to inform the development of standardized classifications by highlighting the strengths and limitations of relying upon any single data source alone.

Methods

This analysis included active component service members (ACSMs) of the U.S. Army, Navy, Air Force, Marine Corps, and Coast Guard; Space Force ACSMs were included with the Air Force. A roster of service members who completed a PHA during 2023, regardless of any tobacco or nicotine use responses, was compiled. Per DOW Instruction 6200.06, service members are required to complete a PHA every 12 months. The PHA provides an annual, standardized health assessment for U.S. military service members to assess individual medical readiness, including occupational and environmental health evaluations, with provision of evidence-based preventive health information and recommendations.⁶

The full roster of service members who completed PHA during 2023, regardless of any tobacco or nicotine use responses, was matched by unique identifiers to query ambulatory and inpatient medical records for each ACSM maintained in the Defense Medical Surveillance System (DMSS). DMSS contains all encounters in military medical and civilian treatment facilities when reimbursed through the Military Health System. From the PHA responses and applicable medical records, evidence of exposure to tobacco or nicotine was classified into 2 separate outcomes: 1) recent use or 2) history of any use.

Recent use

As shown in Table 1, a service member was classified as a ‘recent user’ from the PHA if that service member reported use of any listed tobacco or nicotine product (e.g., cigarette, e-cigarette, chewing tobacco) on at least 1 occasion within the past 30 days. To identify recent tobacco or nicotine use from medical diagnostic codes, we examined medical records for relevant diagnostic codes documented within 30 days, before or after, the PHA sample period (December 1, 2022–January 31, 2024). This method established a standardized documentation period corresponding to the 30-day use period assessed in the survey. Inpatient and ambulatory care records with ICD-10-CM diagnostic codes for nicotine dependence (F17.2*), tobacco use (Z72.0), and tobacco use disorder complicating pregnancy, childbirth and puerperium (O99.33*) were queried from any diagnostic position to document recent nicotine or tobacco use. For the purposes of this study, nicotine dependence and tobacco use disorders were broadly classified as recent tobacco and nicotine use. Service members with resulting medical records matched for these diagnostic codes were classified as positive for diagnostic classification of recent nicotine or tobacco use; conversely, if no applicable medical record was matched, the diagnostic classification was coded as negative.

History of any use

The classification parameters for documenting a history of any tobacco or nicotine use are shown in Table 1; this broader method aims to identify both recent and former users. The PHA classification includes everyone identified by the ‘recent use’ method, but it expands to capture individuals who select the response “I used tobacco in the past, but quit.” To define a history of any nicotine or tobacco use from medical diagnostic codes, applicable medical records were queried for the preceding 20 years through 30 days following the PHA completion period (January 1, 2004–January 31, 2024). Inpatient and ambulatory care records with ICD-9-CM/ICD-10-CM diagnostic codes for nicotine dependence (305.1/F17.2*), tobacco use (Z72.0), tobacco use disorder complicating pregnancy, childbirth and puerperium (649.0*/O99.33*), and personal history of nicotine dependence (Z87.891/V15.82) were queried from any diagnostic position. An ICD-10-CM code for ‘tobacco use’ was introduced in 2015; there is no comparable ICD-9-CM code. Prior to 2015, the only ICD code referencing ‘tobacco use’ was ICD-9-CM 305.1 (‘tobacco use disorder’), which was used to indicate a diagnosis of tobacco dependence. For the purposes of this study, nicotine dependence, tobacco use disorders, or a history of nicotine dependence were broadly classified as past history of tobacco and nicotine use. Service members with resulting medical records matched for these diagnostic codes were classified as positive for diagnostic classification of any nicotine or tobacco use; conversely, if no applicable medical record was matched, diagnostic classification was coded as negative.

Analysis

The dichotomous outcomes for tobacco and nicotine ‘recent use’ and ‘history of any use’ were stratified to assess overlap in classification exposure by data source. Cohen’s kappa was calculated to examine level of agreement between self-reported PHA responses and diagnostic code documentation. To examine demographic differences of recent or history of tobacco or nicotine use by data source classification, we investigated the differences between branch of service, sex, categorized age at date of completion, and racial and ethnic group by separating responses into 1 of the 3 data source categories: concurrent PHA and diagnostic code documentation, exclusive PHA documentation, and exclusive diagnostic code documentation.

Results

Recent use

A total of 921,394 U.S. ACSMs completed a PHA documented in 2023 (Table 2). Among those service members, 22.0% (n=203,156) self-reported recent nicotine or tobacco use on the PHA. The most frequent responses for tobacco or nicotine use within the last 30 days were reported for electronic cigarettes (n=115,486), cigarettes (n=47,325), chewing tobacco (n=45,777), cigars (n=21,517), and other tobacco products (n=9,630).

Among the 921,394 ACSMs who completed a PHA in 2023, 126,777 (13.8%) had a medical record with a diagnostic code for nicotine dependence (n=66,528) or tobacco use (n=88,519) during the period December 1, 2022–January 31, 2024; few service members had a diagnostic code for tobacco use disorder complicating pregnancy (n=1,212) (data not shown). Aggregation of PHA data with exposure determination captured exclusively from diagnostic codes (n=61,038) increased the estimate of recent nicotine or tobacco use to 28.7% (n=264,194). If exposure assessment was limited to medical records, independent of PHA responses, the estimated recent use of tobacco or nicotine exposure for this sample reduced to 13.8% (n=126,777). The Cohen’s kappa statistic of 0.28 indicates a fair level of agreement between the PHA and diagnostic codes for identifying recent tobacco or nicotine use (Table 2).

The demographic distribution of the 264,194 recent tobacco or nicotine users was examined for ACSMs with exclusive PHA exposure (n=137,417, 52.0%), diagnostic coding exclusivity (n=61,038, 23.1%), and concurrent data sources (n=65,739, 24.9%) (Table 2). Compared to other services, the Marine Corps was over-represented in exclusive PHA data documentation versus exclusive diagnostic data (66.1% vs 15.2%). Documentation of tobacco or nicotine use exclusively from the PHA decreased with age, with a substantial difference observed for ACSMs younger than age 25 years (82.0% from PHA vs. 6.7% from diagnostic codes) (Table 3).

History of any use

Of the 921,394 ACSMs who completed a PHA in 2023, 41.1% (n=378,663) self-reported a history of any nicotine or tobacco use (Table 2). A total of 176,004 ACSMs reported using tobacco in the past but had currently quit, whereas all other ACSMs were classified as ‘any use’ from the ‘recent use’ PHA classification criterion.

After matching the PHA respondent roster to medical records for the period January 1, 2004–January 31, 2024, a total of 156,152 ACSMs had an applicable medical record with evidence of any history of tobacco or nicotine use. A total of 52,370 ACSMs had a record for a personal history of nicotine dependence, which did not exceed the total number of medical records identified with diagnoses for tobacco use (n=93,919) or nicotine dependence (n=71,219) (data not shown). Aggregating PHA data with exposure determination captured exclusively from diagnostic codes (n=18,787) only increased the history of any use estimate to 43.1% (n=397,450). If a historical exposure assessment for tobacco or nicotine use was limited to medical records, independent of PHA responses, the estimated ‘any use’ of tobacco or nicotine exposure for this sample drops to 16.9% (n=156,152) The Cohen’s kappa statistic of 0.36 indicates a fair level of agreement between the PHA and diagnostic codes for identifying a history of any tobacco or nicotine use (Table 2).

The demographic distribution of the 397,450 ACSMs with a history of tobacco or nicotine use was examined for those with exclusive PHA exposure (n=241,298, 60.7%), diagnostic coding exclusivity (n=18,787, 4.7%), and concurrent data sources (n=137,365, 34.6%) (Table 4). The Marine Corps represented the highest service-specific proportion of exclusive PHA documentation for tobacco or nicotine use (71.8%) and, consequentially, lowest concurrent PHA and diagnostic code documentation (24.8%). Exclusive PHA documentation decreased with age, while concurrent PHA and diagnostic code documentation increased with age.

Discussion

The results of this study indicate that neither self-reported PHA data nor medical diagnostic codes alone provide a complete picture for all-inclusive classifications of tobacco and nicotine use among ACSMs. To identify recent use, reliance on either PHA data or diagnostic codes in isolation leads to significant under-estimation. Aggregating the 2 sources increased the captured population from 22.0% (PHA alone) to 28.7%. Analysis revealed that over 61,000 recent users would be missed without the inclusion of diagnostic codes. Conversely, the addition of 2 decades of medical records only marginally increased an estimate for history of any use from 41.1% (PHA alone) to 43.1%.

These findings contextualize existing data sources for all-inclusive classifications of tobacco and nicotine use, ranging from self-reported behaviors, clinically documented use, and diagnosed disorders. By comparing self-reported data from the PHA against administrative medical diagnostic codes, this study sought to understand the unique contribution of each source. The Armed Forces Health Surveillance Division (AFHSD) currently maintains standardized classifications for covariates that may typically be included in investigations, such as clinical overweight/obesity and non-medical factors influencing health (e.g., social, environmental and behavioral factors)^12,13; however, tobacco and nicotine use, in addition to other substance abuse disorders such as alcohol dependence, are not currently represented in a standardized surveillance case definition form. The results from this study are intended to inform the development of standardized classifications by highlighting the strengths and limitations of relying on any single data source alone.

The fair level of agreement measured from the Cohen’s kappa statistic indicates there may be substantial non-random differences in the data captured by diagnostic codes and PHA forms. The observed level of agreement for both the ‘recent use’ (78.5%) and ‘history of any use’ (71.8%) classifications demonstrate some consistency between the 2 sources, although not reliably enough to substitute one for the other. They capture different populations, with the PHA more effective for younger service members and the Marine Corps, while diagnostic codes play an increasing role with advancing age. Therefore, a combined surveillance strategy may be critical for accurately monitoring current behaviors and informing targeted interventions.

The assignment of a diagnostic code for tobacco use is often illness-driven, meaning it is more likely to be recorded when a service member seeks care for a related health issue. Consequently, diagnostic codes may over-represent individuals already experiencing tobacco-related health problems, while the PHA provides a broader, more routine representation of use. This may explain why PHA-exclusive data skew heavily toward younger service members, particularly those under age 25 years, who may not yet have developed chronic conditions that would trigger a diagnostic code during a health care visit.

The Marine Corps also represented a higher service-specific proportion of PHA-exclusive data for both recent and historical use. This finding may be due to different health care-seeking behaviors in age groups and branches of service. As the PHA is completed with health care provider supervision,⁶ self-reporting could be biased to avoid perceived negative repercussions of reporting, or could be skewed by service-specific traditions related to tobacco use or health care seeking.^10,11

This study aggregated multiple diagnostic codes into a single category for tobacco and nicotine use. It is important, however, to recognize the distinctions between these codes, as their combination can make the results of comparative analyses difficult to interpret. Clinical practice uses specific ICD-10 codes to differentiate between active tobacco use (Z72.0), nicotine dependence (F17.2*), and personal history of nicotine dependence (Z87.891). While a health care provider can assign a tobacco use diagnosis with individual discretion, a diagnosis of tobacco dependence requires specific clinical and diagnostic criteria. This clinical nuance is not captured in the PHA’s more generalized, self-reported, checked-box format, which focuses on current use patterns rather than formal diagnoses of dependence or historical use.

This assessment is subject to additional limitations. A PHA is recorded as overdue if not completed by 90 days after the due date; thus, ACSMs who were overdue for an annual PHA may not be represented. Additionally, the evaluation of tobacco and nicotine use from medical records may be affected by incomplete data due to coding practices. Although medical codes are specifically allocated to indicate smoking status, an important challenge is whether providers properly document this behavioral risk factor in administrative claims data, which are generated for billing purposes.¹⁴ Additionally, incomplete data may pose a limitation for occurrences of missing medical records. The issue of missing medical records for this cohort is not a significant concern, however. Of the 921,394 ACSMs who completed a PHA in 2023, only 328 had no medical records over the preceding 20-year period.

This analysis did not query open text fields for non-structured data documented on the PHA or within medical record chart notes. One analysis found that 35% of individuals with no structured ICD code for ‘former smoker’ had this information in some form in open text notes on their chart.⁹ Free-text analysis of the standardized PHA survey can provide valuable insights into emerging tobacco and nicotine products not captured by checked-box responses. For instance, nicotine pouches—dissolvable microfiber pouches of nicotine salt powder—have recently gained popularity in the U.S.¹⁵ A convenience-based, self-reported survey indicated that nicotine pouch use among U.S. military personnel is 10 times higher than in the general adult population.¹⁶ Although the current study did not specifically measure nicotine pouch use, a total of 9,630 ACSMs completing a PHA in 2023 reported using an “other” tobacco product. Analyzing the free-text responses associated with this ‘other’ category may reveal more information about emerging product use.

These data are meant to inform future case-finding development processes for tobacco and nicotine use. Additional modifications to the surveillance definitions or matching processes may be required, either to improve estimation accuracy or simplification for routine processing. The 30-day overlap period provided a crude method to match PHA responses with medical records, to account for any variance in 30-day reporting and potential delays in diagnostic documentation. Thus, additional consideration may be required to improve precision of timing between PHA responses and medical diagnostic codes.

The results of this study indicate that neither self-reported PHA data nor medical diagnostic codes alone provide a complete picture of tobacco and nicotine use among ACSMs. The fair level of agreement between sources, particularly for recent use, highlights that each method captures a demographically distinct subset of users, underscoring the need for a multi-faceted approach to public health surveillance. This combined methodological approach may enhance future public health surveillance, improve the accuracy of epidemiological studies, and ultimately provide a stronger evidence base for policies aimed at improving the health and readiness of the force.

References

Public Health Service, Office of the Surgeon General; Samet JM, Pechacek TF, Norman LA, Taylor PL, eds. The Health Consequences of Smoking—50 Years of Progress: A Report of the Surgeon General. Appendix 14.1: tobacco control efforts in the Department of Defense. U.S. Dept. of Health and Human Services;2014. Accessed Dec. 1, 2025. https://www.hhs.gov/sites/default/files/consequences-smoking-appendix14-1-tobacco-control-efforts.pdf
Public Health Service, Office of the Surgeon General; Fagan F, Hickman NJ, Kennedy R, et al, eds. Eliminating Tobacco-Related Disease and Death: Addressing Disparities—A Report of the Surgeon General. U.S. Dept. of Health and Human Services;2024. Accessed Dec. 1, 2025. https://www.hhs.gov/sites/default/files/2024-sgr-tobacco-related-health-disparities-full-report.pdf
Patrick S, Boyle C, LaMorte D, Dore M. Tobacco use prevalence in the Military Health System: a retrospective study. Mil Med. 2024;189(11-12):e2632-e2637. doi:10.1093/milmed/usae208
Institute of Medicine Committee on Smoking Cessation in Military and Veteran Populations; Bondurant S, Wedge R, eds. Combating Tobacco Use in Military and Veteran Populations. National Academies Press;2009. Accessed Mar. 4, 2026. doi:10.17226/12632
Meadows SO, Engel CC, Collins RL, et al. 2018 Department of Defense Health Related Behaviors Survey (HRBS): Results for the Active Component. RAND Corp.;2021. Accessed Dec. 1, 2025. https://www.rand.org/pubs/research_reports/RR4222.html
Office of the Under Secretary of Defense for Personnel and Readiness. DOD Instruction 6200.06. Periodic Health Assessment (PHA) Program. U.S. Dept. of War. Updated Apr. 18, 2025. Accessed Dec. 1, 2025. https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodi/620006p.pdf
Mancuso JD, Ahmed AE, Rossi KR. Tobacco and nicotine use among active component U.S. service members: a comparison of the 2018 estimates from the Health Related Behaviors Survey and the Periodic Health Assessment. MSMR. 2024;31(3):2-12. Accessed Dec. 1, 2025. https://www.health.mil/news/articles/2024/03/01/msmr-tobacco-nicotine-use
Nishi SPE, Zhou J, Young-Fang J, Sharma G, Goodwin J. Trends in tobacco use and tobacco cessation counseling codes among Medicare beneficiaries, 2001–2014. BMC Health Serv Res. 2019;19(548):1-9. doi:10.1186/s12913-019-4368-7
Ruckdeschel JC, Riley M, Parsatharathy S, et al. Unstructured data are superior to structured data for eliciting quantitative smoking history from the electronic health record. JCO Clin Cancer Inform. 2023;7(7). doi:10.1200/cci.22.00155
Nelson JP, Pederson LL, Lewis J. Tobacco use in the Army: illuminating patterns, practices, and options for treatment. Mil Med. 2009;174(2):162-169. doi:10.7205/milmed-d-01-2008
Britt TW, Sipos ML, Klinefelter Z, Adler A. Determinants of mental and physical health treatmentseeking among military personnel. Br J Psychiatry. 2020;217(2):420-426. doi:10.1192/bjp.2019.155
Armed Forces Health Surveillance Division. Surveillance Case Definition for Nonmedical Factors Influencing Health: Social, Environmental, and Behavioral. U.S. Dept. of War. Jul. 1, 2024. Accessed Mar. 17, 2026. https://health.mil/reference-center/publications/2024/07/01/nonmedical-factors-influencing-health-social-environmental-behavioral
Armed Forces Health Surveillance Division. Surveillance Case Definition for Clinical Overweight. U.S. Dept. of War. Oct. 1, 2016. Accessed Mar. 17, 2026. https://health.mil/reference-center/publications/2016/10/01/overweight-obesity
Huo J, Yang M, Shih, Y. Sensitivity of claims-based algorithms to ascertain smoking status more than doubled with meaningful use. Value Health. 2018;21(3):334-340. doi:10.1016/j.jval.2017.09.002
Majmundar A, Okitondo C, Xue A, et al. Nicotine pouch sales trends in the US by volume and nicotine concentration levels from 2019 to 2022. Subst Use Addctn. 2022;5(11):e2242235. doi:10.1001/jamanetworkopen.2022.42235
Little MA, Polaskey KM, Pilehvari A, Krukowski RA, Ribisl KM. Nicotine pouch use among US military personnel. JAMA Netw Open. 2024;7(12):ee2451517. doi:10.1001/jamanetworkopen.2024.51517

Authors’ Affiliation

Epidemiology and Analysis Branch, Armed Forces Health Surveillance Division, Public Health Directorate, Defense Health Agency, Silver Spring, MD: Ms. Rossi, Mr. Russell, Dr. Mabila

Disclaimer

Reportable medical events at Military Health System facilities through week 1, ending January 3, 2026

Wed, 01 Apr 2026 00:00:00 Z

Reportable Medical Events (RMEs) are documented in the Disease Reporting System internet (DRSi) by health care providers and public health officials throughout the Military Health System (MHS) for monitoring, controlling, and preventing the occurrence and spread of diseases of public health interest or readiness importance. These reports are reviewed by each service’s public health surveillance hub. The DRSi collects reports on over 70 different RMEs, including infectious and non-infectious conditions, outbreak reports, STI risk surveys, and tuberculosis contact investigation reports. A complete list of RMEs is available in the 2022 Armed Forces Reportable Medical Events Guidelines and Case Definitions.¹ Data reported in these tables are considered provisional and do not represent conclusive evidence until case reports are fully validated.

Total active component cases reported per week are displayed for the top 5 RMEs for the previous year. Each month, the graph is updated with the top 5 RMEs, and is presented with the current month’s (December 2025) top 5 RMEs, which may differ from previous months. COVID-19 is excluded from these graphs due to changes in reporting and case definition updates in 2023.

References

Armed Forces Health Surveillance Division. Armed Forces Reportable Medical Events. Accessed Feb. 28, 2024. https://health.mil/reference-center/publications/2022/11/01/armed-forces-reportable-medical-events-guidelines
Defense Manpower Data Center. Department of Defense Active Duty Military Personnel by Rank/Grade of Service. Accessed Feb. 28, 2024. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports
Defense Manpower Data Center. Armed Forces Strength Figures for January 31, 2023. Accessed Feb. 28, 2024. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports
Navy Medicine. Surveillance and Reporting Tools–DRSI: Disease Reporting System Internet. Accessed Feb. 28, 2024. https://www.med.navy.mil/navy-marine-corps-public-health-center/preventive-medicine/program-and-policy-support/disease-surveillance/drsi

Authors’ Affiliation

Defense Health Agency, Disease Epidemiology Branch, Defense Centers for Public Health–Aberdeen

Reducing tobacco and nicotine use key to ‘having a healthy, fit force’

Wed, 01 Apr 2026 00:00:00 Z

Tobacco use remains the No.1 preventable cause of death in the U.S., according to the Centers for Disease Control and Prevention, and poses a readiness issue for the military.

The Military Health System is concerned that about one-third of service members still use tobacco and nicotine products — a rate higher than the general population (19%), said Department of War Principal Deputy Assistant Secretary of War for Health Affairs Dr. Stephen Ferrara, citing statistics from department-wide health behavior surveys.

Ferrara spoke on this topic at the National Press Club on the dangers of tobacco use in the military and how the MHS is addressing the issue at an event in March 2026 titled, “Serving Those Who Serve, Embracing Tobacco Harm Reduction.”

Acutely aware of the impacts on readiness, the MHS has long focused on reducing tobacco and nicotine use through a comprehensive approach involving medical, behavioral, and cultural interventions, said Ferrara.

In 2026, that commitment is deeper than ever with the DOW’s deeper emphasis on a healthy force.

“Prevention is in our DNA,” he said. “The way we succeed on the battlefield, of which we're in active operations as we speak, is by having a healthy, fit force.”

As a vascular and interventional radiologist with multiple tours of duty in the U.S. Navy for 25 years, Ferrara is keenly aware that tobacco and nicotine dependence have long been embedded “in the culture” of the military, which offered behavioral off-ramps to smoke.

Ferrara said, “old myths” that tobacco “increases your alertness” have been debunked. “We know now it actually leads to slower wound healing, slower injury healing … especially the cardiovascular” system,” he said.

Stressors associated with military service and cultural dependencies mean “people use different things, whether it's food, whether it's cigarettes, whether it's other habits … as a crutch or as an aid to help them deal with that stress that we asked them to endure.”

The MHS emphasizes a comprehensive approach to help people quit, which includes prevention methods, stop-smoking aids, and behavioral therapies.

Stepping down from tobacco

The MHS provides intermediate, less harmful steps to help service members and veterans put combustible cigarettes down. “We're looking at nicotine replacement or other things that will satisfy or try to give people a bridge so they cannot get the most toxic tobacco experience as a way to eventually get to full cessation,” said Ferrara.

Mitigating “the most harmful behaviors and with a path” away from nicotine and tobacco dependence requires team support, he said. “That's where partnerships come in with the medical community … your friends or your family or your command structure to continue to work that journey from the most harmful behavior to ideally, to not a harmful behavior, with all the intermediate way points.”

Ferrara said the first line of defense against tobacco can be providers, who raise the issue during the annual Periodic Health Assessment or other medical visits. The PHA specifically asks about tobacco or nicotine product use.

“If the answer is yes, we start to talk about how we can do cessation,” Ferrara explained. The MHS has abundant “pharmacologic, mental health therapies, all those things to help people, including other adjunctive therapies, to try to get people to get away from cigarettes.”

MHS works ‘hand in glove’ with the Department of Veterans Affairs

One important effort was the publication in January 2026 of the DOW and the Department of Veterans Affairs joint clinical practice guideline called “Tobacco Use Treatment.”

The CPG describes the critical decision points in tobacco use treatment and presents comprehensive evidence-based recommendations for providers and patients to reduce and then stop the use of tobacco and nicotine. Ferrara emphasized the CPG demonstrates both departments’ commitment to tobacco cessation and continuity in care in transition and afterward.

“Because every veteran was once in uniform, the continuity of care must be instantaneous,” he emphasized. “We'll get you taken care of, and then we need to pass the baton to the VA, and that's why we have that joint clinical practice guideline,” Ferrara explained. “You can see that we are hand in glove with that, and that's as it should be for the folks who serve their country.”

Behavior changes and telehealth

Ferrara highlighted how the military has “really leaned into technology,” including telehealth or virtual appointments for tobacco and nicotine cessation. These tools “support meeting service members where they are in their tobacco-reduction journey, and wherever they are stationed or deployed worldwide,” he said. “It's an exciting time to be in medicine with what's going on in AI (artificial intelligence) and we're being able to leverage those things, not only for diagnostics but also for therapeutics.”

Because most service members are young, “there's a huge appetite for” AI and telehealth, he said. “Most of our service members … grew up very comfortable with technology, and some of them actually prefer a virtual encounter to face-to-face” meetings with a provider.”

He reinforced, “You have to meet people where they are, and I think that's … really a person-centered approach.”

Goal is a healthier, more ready fighting force

“Reducing tobacco and nicotine use improves health, fitness, recovery, and long-term resilience — all of which directly affect the warfighter’s ability to fight and win,” Ferrara said.

“Through continued research, strong partnerships, and sustained leadership commitment, the department is taking concrete steps to drive down tobacco use and protect the health of the men and women who serve,” he stated. “This is about readiness today, and it is also about ensuring that those who serve our nation can enjoy healthier lives long after they retire their uniforms.”

Ferrara noted that he’s already seen a shift in tobacco use. He said over the 35 years that he has been associated with the military, usage and culture have changed, resulting in fewer people smoking.

“If I had the magic wand, I think we would have a culture where we model the behavior that we never get folks started. But until then, we are going to do everything from all the things we talked about and more to mitigate that risk and continue our tobacco harm-reduction techniques.”

Ready to quit? Accessing resources

TRICARE offers a multitude of TRICARE tobacco cessation services. TRICARE covers tobacco cessation counseling if you’re aged 18 or older and you live in one of the 50 states or the District of Columbia, as long as you use a TRICARE-authorized provider.
TRICARE covers prescription and over-the-counter tobacco cessation products at no cost to you if you use TRICARE Pharmacy Home Delivery or a military pharmacy. TRICARE doesn’t cover these products if you get them at a retail network or non-network pharmacy. A TRICARE-authorized provider must write the prescription. You must have a prescription for OTC tobacco cessation products such as nicotine replacement products, nasal sprays, inhalers, patches, gums, and lozenges.
You Can Quit2 is a DOW-supported education program that offers coaching, online tools, and in-person support locators to help you quit tobacco. YCQ quit plan helps you create a timeline that fits your needs so quitting tobacco is within reach.
You can also call your local military hospital or clinic to see if they offer tobacco cessation programs.
The VA offers a wealth of advice on quitting smoking and smokeless products.
If you still use chewing tobacco, do monthly self-checks of your mouth, tongue, throat, face, and neck to help you find possible early signs of damage or cancer.
Smokefree.gov from the National Cancer Institute has many resources and information, including coping with stress without tobacco, what to do if you have a setback quitting tobacco and managing cravings.
The Food and Drug Administration warns that smokeless products have their own dangers.
Smoking and tobacco use from the CDC includes information on nicotine pouches, menthol tobacco products, vaping, secondhand smoke, and much more.

Hospital honors ‘Fighting doctor’ and upholds highest standards of care

Thu, 26 Mar 2026 00:00:00 Z

This year, the Military Health System is celebrating 250 years of America by recognizing the Military Medicine’s enduring history of innovation and impact to the warfighter. Please join the Military Medicine 250 campaign!

Irwin Army Community Hospital, Fort Riley, Kansas, is named for Brig. Gen. Bernard Irwin, who served almost four decades in frontier and wartime posts, between 1849 – 1881. Known as the “fighting doctor,” Irwin did not treat Soldiers from a safe distance — he rode on horseback into battle to reach injured service members and later brought surgical care close to the front lines during the Civil War. The hospital honors Irwin’s namesake through high-quality care for warfighters and their families.

It is fitting that Irwin, for his dedication to warfighter readiness, was chosen as the namesake of a military hospital that honors and supports the 1st Infantry Division at Fort Riley — the U.S. Army’s oldest continuously serving active duty division, and its mission of deploying “in an expeditionary manner to conduct decisive action to fight and win in complex environments as members of a joint, inter-organizational, and multinational team.”

Early years shaped approach to military medicine

Irwin was born in Ireland June 24, 1830, and his family later moved to New York City. He earned a medical degree in 1852 and joined the U.S. Army as an acting assistant surgeon in the mid-1850s, according to his biography from the U.S. Army Medical Department Center of History and Heritage. Irwin was appointed assistant surgeon in 1856 and began a career that would take him across the expanding U.S. frontier.

He served at duty posts in New Mexico and Arizona, including Fort Union, Fort Defiance, and Fort Buchanan conducting field operations, according to his biography. These remote locations forced doctors to solve problems quickly, often with limited supplies and personnel.

While stationed in the Arizona Territory early 1861, he volunteered to take command of a small relief force to aid 2nd Lt. George Bascom and his Soldiers who faced attack near Apache Pass. A story about the event from the AMEDD Center of History and Heritage cites “Irwin and his men rode mules because they had no horses, pushed through severe conditions, reached the trapped unit, and helped drive off the enemy.” The U.S. Army later awarded Irwin the Medal of Honor in 1894 for “distinguished gallantry” in that fight. He also earned his “fighting doctor” moniker from the event.

Wartime hospital care

When the Civil War began, Irwin was assigned to the U.S. Army of the Ohio as the medical director (a term that pre-dates today’s “command surgeon” title) and took part in the campaign that ended in April 1862 at the Battle of Shiloh in Tennessee. There, he organized a tent field hospital the U.S. Army called a first of its kind and “the model upon which our later field hospitals were based.” The location was a surgical station in a farmhouse that was converted into a 300-bed surgical hospital, with an operating room, dispensary, kitchen, and other support spaces, according to the National Park Service.

With the success of the field hospital at Shiloh, Irwin proved concentrating care near the battlefield improved outcomes and reduced mortality, without the need to send wounded troops far distances.

Irwin continued to serve after Shiloh in senior medical roles. His biography indicates or shows promotions during the war, later positions across the western frontier, an assignment in October 1873 to the United States Military Academy at West Point, and retirement in 1894. Congress later promoted him to brigadier general on the retired list in 1904.

Hospital honors legacy through nationally accredited care

The original Irwin Army Community Hospital was dedicated in 1958. In 2016, the legacy hospital was replaced by a new, state-of-the-art $343 million facility, built to carry Irwin’s name into the future, With 47% more space, IACH staff was better positioned to serve about 50,000 beneficiaries, which includes active duty service members, family members, and retirees.

In 2016 and 2024, IACH received the Joint Commission’s “Gold Seal of Approval” for its commitment to providing safe, high-quality patient care. The accreditation involved a four-day onsite review, assessing the performance standards such as emergency management, infection prevention, leadership, medication management, national patient safety goals, and patient rights.

The recognition was “a testament to the unwavering commitment of our staff to upholding the highest standards of safe, quality care for our warfighters and their families,” said Col. Laudino Castillo, hospital commander.

The hospital continues to honor the “fighting doctor” through nationally accredited, exemplary warfighter care, bearing the namesake of Irwin, who “gave no thought to distance, danger, or hardship in answering the many calls for his help,” according to his biography.

2026 Military Health System Research Symposium: Submit your research or nominate outstanding health care work

Tue, 24 Mar 2026 00:00:00 Z

As the 2026 Military Health System Research Symposium, themed “Harnessing the Power of Military Medical Research,” is approaching, participants can submit their abstracts or nominations for the annual awards.

The call for abstracts to submit your research for the Department of War’s premier military medical science meeting closes March 31, 2026, (12 a.m. EST). You can explore sessions and submit at https://mhsrs.health.mil.

Nominations for the 2026 MHSRS Annual Awards are open through April 24, 2026 (12 a.m. EST). These awards honor the researchers and teams whose work strengthens readiness, accelerates medical discovery, and directly supports the deployed warfighter. This is your opportunity to spotlight the people and programs driving meaningful impact across the MHS.

Award categories include:

Distinguished Service
Outstanding Research Accomplishment (Individual/Military) and (Individual/Academia)
Outstanding Research Accomplishment (Team/Military) and (Team/Academia)
Outstanding Program Management (Team)
Warfighter Medical Research Public Communication

You can review full category descriptions and submission criteria on the MHSRS homepage: https://mhsrs.health.mil/MHSRS. You must be registered and logged in to submit an award.

Ensure the award narrative fits the award criteria in the category selected. The Award Review Committee compares the narrative against the criteria. In past years, failure to meet that category's criteria have eliminated some well written packages from award contention.

Please share with colleagues who may be interested.

About MHSRS

The MHSRS is the Department of War’s primary scientific gathering where military medical researchers, clinicians, scientists, and industry partners come together to share new discoveries and improve care for deployed service members.

Incidence and burden of endometriosis among U.S. active component service women, 2017–2024

Sun, 01 Mar 2026 00:00:00 Z

Abstract

Endometriosis is a complex gynecological condition affecting nearly 10% of reproductive-aged women. This report updates a 2017 MSMR report of gynecological conditions, including endometriosis, from 2012 through 2016 among U.S. active component service women. The current report utilized medical encounter data from 2017 through 2024 to assess the incidence of endometriosis and its health care burden among U.S. active component service women. Factors related to co-occurring gynecological conditions, deployment, parity, and contraceptive use were also examined. Crude incidence rates and incidence rate ratios with 95% confidence intervals were calculated. The overall crude rate of endometriosis was 32.8 cases per 10,000 person-years and increased approximately 42.0% from 2017 to 2024. Incidence rates increased with age and were higher among nulliparous and never-deployed service women. Additionally, obese and underweight service women had higher incidence rates. Menorrhagia was the most common co-occurring condition, with oral birth control the most common form of contraceptive among incident cases. Identification of at-risk service women may help formulate targeted policies for earlier diagnosis to improve both quality of life and military readiness.

What are the new findings?

Incidence of endometriosis increased during the surveillance period, from 28.7 cases per 10,000 person-years in 2017 to 40.7 cases per 10,000 person-years in 2024, coincident with a general increase of medical encounters for endometriosis, from 2,740 medical encounters in 2017 to 3,864 medical encounters in 2024. Service women who were older, obese or underweight, nulliparous, and never deployed had higher incidence rates.

What is the impact on readiness and force health protection?

Endometriosis is associated with a multitude of symptoms and co-occurring gynecological conditions that can negatively affect daily life, military readiness, and deployability. These findings enable the Military Health System to better identify at-risk service women and formulate policies for earlier diagnosis and treatment, improving quality of life in addition to preserving military readiness.

Background

Endometriosis is a complex gynecological condition in which endometrial-like tissue grows outside the uterus.¹ Symptoms of endometriosis include dysmenorrhea, dyspareunia, severe pelvic pain, and infertility, although some women present as asymptomatic.² Approximately 10% of reproductive-age women are affected by this condition^2,3; however, true prevalence may be under-estimated due to differing case criteria and diagnostic biases in many studies.^3,4 Furthermore, prevalence estimates may be influenced by the use of surgical visualization to obtain definitive diagnosis in addition to delays in surgical diagnosis from symptom onset, which average 7 years.⁵ Socio-demographic characteristics, reproductive history, contraception use, personal habits, and body characteristics have been evaluated as potential risk and protective factors for endometriosis, but the literature is inconsistent.^2,6

Women account for approximately 17% of U.S. active component service members, of whom approximately 98% are of reproductive age (ages <20–49 years).⁷ From 2012 to 2016, endometriosis affected an average of 1,113 U.S. active component service women (ACSW) annually, accounting for an annual average of 2,470 medical encounters and 195 bed days each year.⁸ Those findings suggest a significant loss of duty time for ACSW due to endometriosis, as well as a heavy burden on the Medical Health System (MHS). Older ACSW, those in the Army, and non-Hispanic Black service women were reported to have higher incidences of endometriosis than their respective counterparts.⁸ Co-occurring conditions, including menorrhagia, polycystic ovarian syndrome (PCOS), and uterine fibroids, may also put service women at a higher risk for endometriosis.⁸

Risk and protective factors for endometriosis are inconsistent in the literature.^2,9 Among protective factors, an inverse relationship between body mass index (BMI) and endometriosis has been demonstrated.^2,6 Furthermore, women of greater parity have also shown reduced risk of endometriosis when compared to nulliparous women and women with lower numbers of pregnancies.^10,11 In addition, current or recent oral contraceptive use (risk ratio 0.4; 95% CI 0.2, 0.7) reduced risk of endometriosis by 60% compared to never-users; however, protective effects of oral contraceptives dissipate among former users.² While current or recent intrauterine device (IUD) use has demonstrated reduced risk of endometriosis, other studies have shown no association between IUDs and endometriosis diagnosis.²

From 2012 to 2016, the incidence of endometriosis among ACSW was reported as 30.8 cases per 10,000 person-years (p-yrs).⁸ This rate is notably higher than a 2006–2015 U.S. population-based study that reported an average incidence rate (IR) of 24.3 cases per 10,000 p-yrs.¹² While health care accessibility and affordability provided by the MHS could explain the higher incidence of endometriosis in the military population, when compared to the civilian population, there is no clear reason why military women are more likely to suffer from endometriosis. Military service-related effects—of deployment, mental health, and reproductive health—could offer other explanations for this anomaly, however.^9,13

Combat ACSW must be mission ready to deploy; endometriosis and symptomology may hinder this ability, however. Furthermore, combat-related deployments have been linked to physical and mental health issues.^14,15 Female veterans of Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) with mental health issues were more likely to receive a diagnosis of endometriosis compared to female veterans without mental health issues; differences were not found to be due to demographics, service characteristics, or primary care.⁹ Negative coping strategies due to personal- and deployment-related stressors may influence reproductive health risks such as unintended pregnancy or deprioritized reproductive health care.¹³ Additionally, women who served in OEF, OIF, and Operation New Dawn (OND) with deployments longer than 9 months were more likely to be diagnosed with infertility,¹⁵ a condition linked to endometriosis.² A recent report of ACSW of reproductive potential found incidence of infertility at 77.5 cases per 10,000 p-yrs¹⁶; infertility affects 30.0–50.0% of women with endometriosis.¹⁷ These effects not only raise concerns about reproductive health but force readiness overall.

Previous reports on gynecological disorders among ACSW showed decreased overall annual incidence for all conditions evaluated—with the exceptions of endometriosis and uterine fibroids; IRs for endometriosis and uterine fibroids remained stable.⁸ While updated incidence and burden research for uterine fibroids exists,¹⁸ there is a lack of literature singularly focused on endometriosis among ACSW.

While several factors have been consistently observed as protective against diagnosis for endometriosis, those findings have not been widely reported for military populations. The purpose of this study was to assess the incidence of endometriosis diagnosis and its health care burden among U.S. ACSW. Due to the lag in time between onset and diagnosis, true incidence of endometriosis could be determined; therefore, all references to incidence in this report refer to diagnosis incidence rather than onset of symptom incidence. Compared to prior research on this population,⁸ relationships between incident endometriosis and deployment, BMI, parity, and contraceptive use were explored, as these factors may influence endometriosis diagnoses. Co-occurring gynecological conditions and endometriosis were also analyzed, similar to previous reporting,⁸ to help better understand the reproductive health of ACSW.

Methods

Study population

The study population consisted of all ACSW ages 17–62 years in any branch of service of the U.S. Armed Forces, excluding the Coast Guard, from January 1, 2017 through December 31, 2024. Demographic, deployment, and inpatient and ambulatory care medical encounter records were obtained from the Defense Medical Surveillance System (DMSS); deployment data, only available through December 2022, were analyzed to determine numbers and lengths of deployments at any time prior to incident dates. Demographic variables included age, service branch, racial or ethnic group, rank, marital status, BMI, and occupation. BMI was obtained through the Defense Centers for Public Health–Portsmouth (DCPH-P) MHS Data Repository (MDR) and Periodic Health Assessments (PHAs). BMI records were excluded if height was less than or equal to 1 meter (m); height greater than or equal to 2.5 m; weight less than or equal to 20 kilograms (kg); weight greater than or equal to 180 kg; or obtained during pregnancy. The BMI record closest to the incident date was used for cases, while the BMI record closest to the start of a service record was used for the remaining population.

International Classification of Diseases, 9th and 10th revisions, Clinical Modification (ICD-9-CM/ICD-10-CM) codes were used to determine endometriosis diagnoses and co-occurring gynecological conditions, including menorrhagia, PCOS, uterine fibroids, and infertility (Table 1). In addition to ICD-9-CM/ICD-10-CM codes, Procedure Coding System (ICD-9-PCS/ICD-10-PCS) codes and Current Procedural Terminology (CPT) codes were used to identify prior parity and current contraceptive use (Table 1).

Parity was defined as a delivery-related code (Table 1) in any diagnostic position prior to the incident date. Delivery events were counted once every 280 days and recorded as a binary variable (‘yes’ or ‘no’) and as a categorical variable representing the number of births (0–3+). Current contraceptive use was defined as use of at least 1 contraceptive type: implant, injection, IUD, oral birth control, patch, vaginal ring, or miscellaneous type (i.e., unspecified or not already listed). Service women were counted once per category. Current use for long-acting contraceptives was determined within 5 years preceding the incident date for IUDs and within 3 years preceding the incident date for implants; all other contraceptive types were determined as current use within 12 months preceding the incident date. Pharmaceutical data were also utilized to analyze contraceptive use for implants, injections, IUDs, oral birth control, patches, and vaginal rings (Table 1).

Case definition

A case of endometriosis was defined as an individual with 1 inpatient encounter with a case-defining code in any diagnostic position or 2 ambulatory encounters within 180 days with a case-defining code in any diagnostic position.⁸ Individuals were counted as an incident case once per lifetime.⁸

Menorrhagia was defined as an individual with 1 inpatient encounter with a case-defining code in the primary diagnostic position or 2 ambulatory encounters within 180-day period with a case-defining code in any diagnostic position.¹⁹ Menorrhagia cases were counted once every 365 days.¹⁹ PCOS was defined as an individual with 1 inpatient encounter with a case-defining code in the primary or secondary diagnostic position, or 2 ambulatory encounters in any diagnostic position.²⁰ Uterine fibroids were defined as 1 inpatient or ambulatory encounter with a case-defining code in the primary diagnostic position, or 1 inpatient or ambulatory encounter with a case-defining code in the secondary diagnostic position and at least 1 associated symptom (Table 1) in the primary diagnostic position.²¹ Infertility was defined as 1 inpatient encounter with a case-defining code in the primary diagnostic position or 2 ambulatory encounters with a case-defining code in the primary or secondary diagnostic position.²² PCOS and uterine fibroids counted once per lifetime, while infertility was counted once per surveillance period.^20-22

Statistical analysis

Crude IRs for demographic variables and case year were calculated per 10,000 p-yrs. Parity and deployment were stratified by count, while contraceptive use was categorized by type, to assess trends. Incident rate ratios (IRRs) and 95% confidence intervals (CIs) were then calculated for baseline characteristics. Prior parity and deployment may include person-time occurring outside the surveillance period; therefore, overall person-time was used to calculate crude IRs. IRRs were not calculated for prior characteristics, as using the overall person-time produced non-comparable rate contrast. To estimate the health care burden of endometriosis, medical encounters with a case-defining code in the primary diagnostic position were examined to evaluate the total numbers of medical encounters, individuals affected, and hospital bed days. All analyses were conducted using SAS^® Enterprise Guide^® software (version 8.3, SAS Inst., Inc., Cary, NC).

Results

During the 8-year surveillance period, 5,733 ACSW, or 1.3% of all eligible service women during the period, were diagnosed with an incident case of endometriosis, at an overall rate of 32.8 cases per 10,000 p-yrs (Table 2).

Overall, non-Hispanic Black women (IRR 1.1, 95% CI 1.1, 1.2) and women in health care occupations (IRR 1.7, 95% CI 1.5, 2.1) (Table 2) were more likely to be diagnosed with incident endometriosis than their counterparts. Additionally, women with a marital status of married (IRR 2.1, 95% CI 1.9, 2.2) or other (IRR 2.3, 95% CI 2.1, 2.5) were twice as likely to be diagnosed with incident endometriosis.

Rates of incident endometriosis increased with age, with women ages 40 years or older demonstrating the highest IR overall (69.8 cases per 10,000 p-yrs) (Table 2). This trend was generally observed throughout the surveillance period (data not shown). Overall, compared to ACSW of normal BMI, overweight women were 31.0% more likely to be diagnosed with incident endometriosis, while underweight women were 57.0% more likely, and obese women were 97.0% more likely to be diagnosed with endometriosis (Table 2).

Among women with incident endometriosis, 23.1% had co-occurring menorrhagia, while 21.1% had co-occurring infertility, 9.8% had co-occurring uterine fibroids, and 7.3 had co-occurring PCOS (data not shown).

Endometriosis cases with no prior deployments had higher IRs (19.1 cases per 10,000 p-yrs) compared to women with prior deployments (13.7 cases per 10,000 p-yrs) (Table 3). Among women with prior deployments, women with 1 deployment had the highest IR (6.3 cases per 10,000 p-yrs) (Table 3). On average, prior deployments lasted approximately 6 months and occurred about 9 years prior to the incident endometriosis diagnosis (Table 3). Additionally, nulliparous women had a higher IR (22.3 cases per 10,000 p-yrs) compared to uniparous and multiparous women (10.5 cases per 10,000 p-yrs) (Table 3). With each delivery, IRs of endometriosis decreased (Table 3).

Among women with incident endometriosis, 24.0% were not currently using any form of contraceptive, while 76.0% were currently using some form of contraceptive (Figure 2). Oral birth control was the most common (23.1%) type of contraceptive used by ACSW, followed by miscellaneous type (22.2%) and IUDs (16.7%) (Figure 2).

Figure 3 presents the burden of endometriosis among ACSW. The majority of 2017–2024 medical encounters for endometriosis were ambulatory care encounters (Figure 3). The number of medical encounters remained relatively stable before 2021, when a continued annual increase began (Figure 3). The number of individuals with medical encounters decreased in 2018, but since 2020 counts have increased, along with medical encounters (Figure 3). The number of hospital bed days was at its lowest in 2021, while only 2 years later, in 2023, the highest number of hospital bed days was recorded. Counts more than doubled in 2023 compared to the previous year, but this is attributed to a small number of individuals rather than a reflection of the entire population (Figure 3).

Discussion

This study analyzed incidence of diagnosis rates of endometriosis, and this report describes the distributions of prior deployment, parity, and BMI on IRs. Co-occurring gynecological conditions, current contraceptive use, and health care burden were examined as well. Compared to the prior MSMR report on endometriosis,⁸ overall crude incidence of endometriosis has increased from 30.8 cases per 10,000 p-yrs during 2012-2016 to 32.8 cases per 10,000 p-yrs in 2017-2024. During the surveillance period, IRs increased nearly 42.0% from 2017 to 2024. The current findings suggest an upward trend of newly diagnosed endometriosis among ACSW. When compared to civilian women, ACSW have greater accessibility to health care and diagnosis, provided by MHS, which may explain the increase in endometriosis diagnosis, rather than reflect a true increase in cases.

Consistent with the prior reporting of endometriosis among ACSW,⁸ service women who were older, non-Hispanic Black race or ethnicity, and in health care occupations had higher rates of endometriosis; similar findings for age at diagnosis were reported for the general population.¹¹ Civilian women ages 36-45 years were found to have higher IRs of endometriosis.¹¹ Delayed diagnosis from symptom onset could explain why IRs are higher among women ages 35 years or older compared to younger service women.

Differences between racial and ethnic groups appear to be unique to the military population, when compared to the general population. Several studies have found lower incident endometriosis among non-Hispanic Black women compared to non-Hispanic White women, or no significant difference at all.^11,23,24 Disparities in civilian health care and need for surgical diagnosis may explain differences among military and civilian rates.²³ Further exploration of higher IRs of endometriosis among non-Hispanic Black women compared to civilian populations may be warranted.

Service women with no deployment history prior to endometriosis diagnosis had higher IRs of endometriosis compared to those with prior deployments, while women with 1 deployment had higher IRs than women with multiple deployments. These findings are somewhat unexpected, given the epidemiological associations between deployment and adverse reproductive and mental health outcomes.^9,15 The IRs are crude, however, and therefore the observed difference may be due to unadjusted confounding variables rather than a true statistical difference in risk. Combat trauma could negatively influence mental health, leading to riskier sexual behaviors and avoidance of reproductive health care¹¹; these factors lead to poorer reproductive health outcomes.¹³

Determining the effects of deployment on endometriosis are difficult, however, due to the timing of disease onset and disease diagnosis. In this study, deployment occurred approximately 9 years, on average, prior to endometriosis diagnosis. Additionally, women with endometriosis demonstrate poor physical performance compared to women without the condition,²⁵ which may disqualify women from deployment, possibly inferring the ‘healthy warrior effect’, with healthier ACSW more likely to deploy. Furthermore, less than 4% of incident cases deployed following diagnosis (data not shown). These findings suggest that endometriosis diagnosis may inhibit deployment of ACSW and require greater medical management of ACSW to maintain force readiness.

BMI is reported to have an inverse relationship with endometriosis,^2,6 and in this study underweight women did have overall higher crude IRs than overweight women; this finding was not evidenced throughout the surveillance period, however (data not shown). Obese service women were observed to have the highest incidence of endometriosis overall, and throughout the study. Previous research found that this inverse relationship of BMI and endometriosis was not evident among women ages 30 years or older.²⁶ When this study examined BMI by age group, underweight ACSW ages 25-34 years had the highest IRs, while in all other age groups, obese ACSW had the highest rates (data not shown). These findings support the previous research,²⁶ suggesting a greater association of underweight BMI with younger ACSW and endometriosis diagnosis.

Lower parity was associated with higher rates of endometriosis. Given the association between infertility and endometriosis,¹⁷ these findings may be unsurprising, however. In this population, 21.1% of women with incident endometriosis also had co-occurring infertility. Additionally, the majority of endometriosis cases in this population were currently using contraceptives prior to diagnosis. Pregnancy prevention is not the only indication for contraceptive use, as oral contraceptives are a primary or ‘first-line’ treatment for endometriosis and endometriosis-associated symptoms.²⁷ Oral birth control was the most common contraceptive type among women in this population.

Several limitations are important to consider when interpreting these findings. The delay in obtaining endometriosis diagnosis5 creates a challenge for determining disease onset and how reproductive health, demographic, and service-related factors affect the condition. The IRs for prior parity and prior deployment were calculated using overall person-time due to an inability to calculate person-time prior to diagnosis for the population at risk, as not all ACSW at risk in the population were diagnosed with endometriosis. Additionally, the ‘healthy warrior effect’ may explain higher IRs among ACSW with no deployment history compared to those with deployment history. The crude IRs for prior parity and prior deployment should be evaluated as preliminary and with caution. Lack of a standardized case definition for endometriosis in the literature presents comparison challenges.^3,4 Additionally, the difficulty of obtaining a diagnosis may obscure true incidence. Furthermore, results related to parity and contraceptive use are observational. Reasons why women are nulliparous or contraceptive users are numerous and unknown in this study. Finally, deployment data were only available through 2022, under-estimating rates of prior deployment among ACSW.

Endometriosis is associated with a multitude of symptoms² that can affect military readiness and quality of life. Future studies should evaluate endometriosis severity to understand its effects on force readiness and health care provision. A more comprehensive cohort study of symptomology, mental health, deployment, and demographics, from accession to end-of-service contract, may better explain the effects of military service on endometriosis.

References

Sarria-Santamera A, Orazumbekova B, Terzic M, et al. Systematic review and meta-analysis of incidence and prevalence of endometriosis. Healthcare (Basel). 2020;9(1):29. doi:10.3390/healthcare9010029
Eskenazi B, Warner ML. Epidemiology of endometriosis. Obstet Gynecol Clin North Am. 1997;24(2):235-258. doi:10.1016/s0889-8545(05)70302-8
World Health Organization. Endometriosis. 2023. Accessed Feb. 17, 2026. https://www.who.int/news-room/fact-sheets/detail/endometriosis
Harder C, Velho RV, Brandes I, Sehouli J, Mechsner S. Assessing the true prevalence of endometriosis: a narrative review of literature data. Int J Gynaecol Obstet. 2024;167(3):883-900. doi:10.1002/ijgo.15756
Nnoaham KE, Hummelshoj L, Webster P, et al. Impact of endometriosis on quality of life and work productivity: a multicenter study across ten countries. Fertil Steril. 2011;96(2):366-373.e8. doi:10.1016/j.fertnstert.2011.05.090
Shafrir AL, Farland LV, Shah DK, et al. Risk for and consequences of endometriosis: a critical epidemiologic review. Best Pract Res Clin Obstet Gynaecol. 2018;51:1-15. doi:10.1016/j.bpobgyn.2018.06.001
McQuistan AA, Dreyer E, Mabila SL. Midyear populations by sex, age, and race and ethnicity of active component service members of the U.S. Armed Forces, 2018–2022. MSMR. 2023;30(12):12. Accessed Feb. 17, 2026. https://www.health.mil/news/articles/2023/12/01/msmr-midyear-populations
Stahlman S, Williams VF, Taubman SB. Incidence and burden of gynecologic disorders, active component service women, U.S. Armed Forces, 2012–2016. MSMR. 2017;24(11):30-38. Accessed Feb. 17, 2026. https://www.health.mil/reference-center/reports/2017/01/01/medical-surveillance-monthly-report-volume-24-number-11
Cohen BE, Maguen S, Bertenthal D, et al. Reproductive and other health outcomes in Iraq and Afghanistan women veterans using VA health care: association with mental health diagnoses. Womens Health Issues. 2012;22(5):e461-e471. doi:10.1016/j.whi.2012.06.005
Parazzini F, Ferraroni M, Fedele L, et al. Pelvic endometriosis: reproductive and menstrual risk factors at different stages in Lombardy, northern Italy. J Epidemiol Community Health. 1995;49(1):61-64. doi:10.1136/jech.49.1.61
Missmer SA, Hankinson SE, Spiegelman D, et al. Reproductive history and endometriosis among premenopausal women. Obstet Gynecol. 2004;104(5 pt 1):965-974. doi:10.1097/01.aog.0000142714.54857.f8
Christ JP, Yu O, Schulze-Rath R, et al. Incidence, prevalence, and trends in endometriosis diagnosis: a United States population-based study from 2006 to 2015. Am J Obstet Gynecol. 2021;225(5):500.e1-500.e9. doi:10.1016/j.ajog.2021.06.067
Gawron LM, Mohanty AF, Kaiser JE, Gundlapalli AV. Impact of deployment on reproductive health in U.S. active-duty servicewomen and veterans. Semin Reprod Med. 2018;36(6):361-370. doi:10.1055/s-0039-1678749
McAndrew LM, D’Andrea E, Lu SE, et al. What pre-deployment and early post-deployment factors predict health function after combat deployment?: a prospective longitudinal study of Operation Enduring Freedom (OEF)/Operation Iraqi Freedom (OIF) soldiers. Health Qual Life Outcomes. 2013;11:73. doi:10.1186/1477-7525-11-73
Armed Forces Health Surveillance Center. Health of women after wartime deployments: correlates of risk for selected medical conditions among females after initial and repeat deployments to Afghanistan and Iraq, active component, U.S. Armed Forces. MSMR. 2012;19(7):2-10. Accessed Feb. 17, 2026. https://www.health.mil/reference-center/reports/2012/01/01/medical-surveillance-monthly-report-volume-19-number-7
Armed Forces Health Surveillance Division. Infertility among active component service women, U.S. Armed Forces, 2019–2023. MSMR. 2025;32(5):19-25. Accessed Feb. 17, 2026. https://www.health.mil/news/articles/2025/05/01/msmr-female-infertility
Llarena NC, Falcone T, Flyckt RL. Fertility preservation in women with endometriosis. Clin Med Insights Reprod Health. 2019;13:1179558119873386. doi:10.1177/1179558119873386
Nieh C, Mabila SL. Incidence and health care burden of uterine fibroids among female service members in the active component of the U.S. Armed Forces, 2011–2022. MSMR. 2024;31(2):9-15. Accessed Feb. 17, 2026. https://www.health.mil/news/articles/2024/02/01/msmr-uterine-fibroids
Armed Forces Health Surveillance Division. Surveillance Case Definition: Menorrhagia. Defense Health Agency, U.S. Dept. of War. 2015. Accessed Feb. 17, 2026. https://www.health.mil/reference-center/publications/2015/01/01/menorrhagia
Armed Forces Health Surveillance Division. Surveillance Case Definition: Polycystic Ovarian Syndrome. Defense Health Agency, U.S. Dept. of War. 2015. Accessed Feb. 17, 2026. https://www.health.mil/reference-center/publications/2015/01/01/polycystic-ovarian-syndrome
Armed Forces Health Surveillance Division. Surveillance Case Definition: Uterine Leiomyomas (Fibroids). Defense Health Agency, U.S. Dept. of War. 2015. Accessed Feb. 17, 2026. https://www.health.mil/reference-center/publications/2015/01/01/uterine-leiomyomas
Armed Forces Health Surveillance Division. Surveillance Case Definition: Female Infertility. Defense Health Agency, U.S. Dept. of War. 2018. Accessed Feb. 17, 2026. https://www.health.mil/reference-center/publications/2018/09/01/female-infertility
Katon JG, Plowden TC, Marsh EE. Racial disparities in uterine fibroids and endometriosis: a systematic review and application of social, structural, and political context. Fertil Steril. 2023;119(3):355-363. doi:10.1016/j.fertnstert.2023.01.022
Bougie O, Yap MI, Sikora L, Flaxman T, Singh S. Influence of race/ethnicity on prevalence and presentation of endometriosis: a systematic review and meta-analysis. BJOG. 2019;126(9):1104-1115. doi:10.1111/1471-0528.15692
Silva T, Oliveira M, Oliveira E, et al. Are women with endometriosis more likely to experience reduced physical performance compared to women without the condition? PeerJ. 2024;12:e16835. doi:10.7717/peerj.16835
McCann SE, Freudenheim JL, Darrow SL, Batt RE, Zielezny MA. Endometriosis and body fat distribution. Obstet Gynecol. 1993;82(4 pt 1):545-549. doi:10.1097/00006250-199310000-00014
Casper RF. Progestin-only pills may be a better first-line treatment for endometriosis than combined estrogen-progestin contraceptive pills. Fertil Steril. 2017;107(3):533-536. doi:10.1016/j.fertnstert.2017.01.003

Authors’ Affiliation

Epidemiology and Analysis Branch, Armed Forces Health Surveillance Division, Public Health Directorate, Defense Health Agency, Silver Spring, MD

Acknowledgments

The authors thank Alexis A. McQuistan, MPH, Epidemiology and Analysis Branch, Armed Forces Health Surveillance Division, for her helpful comments and suggestions during the review process.

Disclaimer

The authors of this report are employees of the U.S. Government. This work was prepared as part of official duties. Title 17, U.S. Code Section 105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S. Code Section 101 defines a U.S. Government work as a work prepared by an employee of the U.S. Government as part of that person’s official duties.

Surveillance snapshot: Mid-year populations by sex, age, and race and ethnicity of U.S. active component service members, 2023–2025

Sun, 01 Mar 2026 00:00:00 Z

This Surveillance Snapshot describes the mid-year population for active component service members (ACSMs) of the U.S. Army, Navy, Air Force, Marine Corps, Space Force, and Coast Guard from 2023 to 2025, stratified by age, sex, and race and ethnicity. Population counts were obtained from June of each calendar year using personnel data from the Defense Manpower Data Center (DMDC) maintained in the Defense Medical Surveillance System (DMSS). Counts and percentages were stratified by sex, age group, and race and ethnicity.

In DMSS, race and ethnicity are categorized as non-Hispanic White, non-Hispanic Black, Hispanic, Asian/Pacific Islander, and American Indian/Alaskan Native, and Other. Both sex and race and ethnicity are self-reported by individual service members. As of 2021, the values for Asian/Pacific Islander and American Indian/Alaskan Native are not populated in DMSS for the Air Force and Coast Guard, and these 2 groups have been included in the ‘other’ category for this report.

The minimum and maximum mid-year populations of ACSMs ranged from 1,063,862 to 1,085,521 among men and 230,260 to 240,065 among women during the surveillance period. Demographic shifts among ACSMs varied by age and sex. In 2025, 81.8% of the active component was comprised of men, and 18.2% was comprised of women (Table). Stratified by age, the proportion of women was highest among the younger than age 20 years group (21.3%) and lowest in the ages 50-54 years group (15.1%).

Overall, while non-Hispanic White service members represented the largest proportion by race and ethnicity in 2025, that proportion declined over the surveillance period. The proportion of Hispanic service members increased throughout the surveillance period, continuing a recent trend.¹ The greatest demographic shifts are seen in the younger than age 20 years group, with the greatest percent increase in numbers among service members identifying as Black, non-Hispanic, Hispanic, and ‘other’ for both sexes. Among female service members younger than age 20 years, those identifying as Hispanic constituted the largest group (35.4%) in 2025. Similar trends are seen among male service members younger than age 20 years, where non-Hispanic White male service members represented less than half of men in that age group (46.7%), and the proportion of Hispanic men has increased since 2023 (29.5%). Among older age groups, demographic shifts are less pronounced. These data can be used to provide additional context for health surveillance analyses for U.S. ACSMs.

Reference

McQuistan A, Dreyer E, Mabila S. Mid-year populations by sex, age, and race and ethnicity of active component service members of the U.S. Armed Forces, 2018–2022. MSMR. 2023;30(12):12. Accessed Feb. 26, 2026. https://health.mil/reference-center/reports/2023/12/01/msmr-vol-30-no-12-dec-2023

Mortality rates among U.S. service members, 2010–2020

Sun, 01 Mar 2026 00:00:00 Z

Abstract

This report updates previous summaries of the numbers, rates, trends and causes of death among U.S. active component, National Guard, and reserve component members from 2010 through 2020. Mortality rates among service members in all components decreased from 2011 to 2014, corresponding with a drawdown of U.S. military operations in U.S. Central Command. Compared to their respective counterparts, all-cause mortality rates were highest in the guard and reserve component and among Army soldiers, male service members, non-Hispanic White individuals, those in the oldest age category (age 55 years and older), and service members in combat-related occupations. Suicide and self-inflicted injury was the leading cause of death for both U.S. service women and men. Mortality rates for all causes of death among military service members were lower than the in U.S. population after adjustments for age, sex, and race and ethnicity—with the exception of suicide and self-inflicted injury, for which rates were higher. These findings demonstrate the need for a continued emphasis on suicide prevention programs to improve service member well-being. By identifying the specific subpopulations at highest risk for various causes of mortality, these surveillance data provide information for the Department of War to refine and more effectively target its prevention efforts and resources. Continued mortality surveillance is essential to identify emerging threats, evaluate the effectiveness of interventions, and protect both the health and readiness of the force.

What are the new findings?

Mortality rates decreased from 2011 to 2014, corresponding with the drawdown of U.S. military operations in U. S. Central Command. The leading cause of death for both female and male service members was suicide and self-inflicted injury. After adjustments for age, sex, and race and ethnicity, service members had lower mortality rates than the U.S. general population, with the exception of mortality rates due to suicide and self-inflicted injury.

What is the impact on readiness and force health protection?

The findings of this report underscore the importance for enhancing and improving the design of suicide prevention programs within the military. While suicide is a leading cause of death for service members, the report highlights other potentially preventable causes of death that require ongoing investigation and monitoring, such as accidents and natural causes.

Background

Military medical surveillance activities are designed and conducted to identify significant threats to the health, fitness, and operational effectiveness of military populations. Tracking mortality data, particularly the deaths of active duty service members, is crucial for maintaining force readiness. Systematic review of mortality data can detect previously unknown or under-recognized threats, inform program and policy development, guide resource allocation, and assess the effectiveness of prevention efforts.

Applicants for U.S. military service are rigorously screened to ensure physical and psychological fitness for their roles. The U.S. military provides extensive health promotion, safety, and force health protection programs to its service members in addition to offering free preventive, curative, and rehabilitative medical services. Despite these efforts, deaths from preventable injuries (e.g., combat-related, accidental, self-inflicted) remain a concern.^1-4

All-cause mortality surveillance is essential to characterize the numbers, natures, risk factors, and causes of preventable deaths among active duty service members. MSMR last published a comprehensive mortality report for all service branches in 2014.⁴ From 1998 to 2011, accidental deaths were the most common manner of death for active component service members, while suicide was the most common manner of death from 2012 to 2013.⁴ Transportation deaths declined steadily during that period, and combat-related deaths declined sharply in 2012 and 2013.⁴ The current report provides an overview of all-cause mortality, updating previous summaries and including deaths from active as well as guard and reserve component service members of the U.S. Armed Forces from 2010 through 2020.

Methods

The surveillance population included all individuals who served in the U.S. military during the surveillance period as a member of the active or guard and reserve components of the U.S. Army, Navy, Air Force, Marine Corps, or Coast Guard from January 1, 2010 through December 31, 2020. The outcome of interest for this report was deaths of active, guard and reserve component members while in military service. This study received a determination of ‘Not Research’ by the DHA Office of Research Protections on February 14, 2023.

Mortality data were obtained from the U.S. Department of Veterans Affairs and Department of Defense (VA/DOD) Mortality Data Repository, which compiles National Death Index (NDI) records for all veterans and military service members. These data were requested through the Defense Suicide Prevention Office (DSPO) and obtained in July 2023. That information was then merged with Defense Manpower Data Center (DMDC) demographic records, which are routinely provided for surveillance purposes to the Armed Forces Health Surveillance Division for integration within the Defense Medical Surveillance System (DMSS), to identify demographic characteristics and calculations of mortality rates. A death was considered to have occurred ‘in service’ if it occurred within the beginning and end dates (or within 90 days after last date) of a service member’s DMDC demographic record. Deaths were included regardless of whether a service member was on active duty status at time of death.

Underlying causes of death were grouped into the 26 cause of death categories in the Surveillance, Epidemiology, and End Results Program (SEER) cause of death recode instructions (which include non-neoplasm causes of death).⁵ Deaths that could not be categorized (n=1,420) by the initial 26 SEER cause of death categories were reviewed by the Armed Forces Medical Examiner System (AFMES) for additional clarification on underlying cause; if additional information was available, those deaths were then categorized as ‘other accidents and adverse effects’, ‘suicide and self-inflicted injury’, or ‘homicide and legal intervention’. Deaths determined to be due to natural or undetermined causes remained uncategorized. After review of the data, all 26 defined cause of death categories with rates less than 1 per 100,000 person-years were collapsed into a single category: ‘all other causes’. After the consolidation of cause of death categories with rates less than 1 per 100,000 person-years into the ‘all other causes’ category, 8 final cause of death categories remained: suicide and self-inflicted injury (International Classification of Diseases, 10th Revision [ICD-10]: U03, X60–X84, Y87.0), transport accidents (ICD-10: V01–V99, Y85), other accidents and adverse effects (ICD-10: W00–W99, X00–X59, Y86), neoplasm (ICD-10: C00–C97, D00–D48), operations of war (ICD-10: Y36, Y89.1), diseases of heart (ICD-10: I00–I09, I11, I13, I20–I51), homicide and legal intervention (ICD-10: U01–U02, X85–Y09, Y35, Y87.1, Y89.0), and all other causes.

Summary measures for this analysis are numbers of deaths in the surveillance population overall and mortality rates calculated as deaths per 100,000 person-years of military service. Mortality rates were summarized in relation to person-years at risk rather than individuals at risk because the U.S. military is a dynamic cohort, with many individuals entering and leaving service on any day. In any calendar year, there are many more individuals with any service than there are total person-years of active service; the latter was considered a more consistent measure of exposure to mortality risk across calendar years.

The final cause of death categories including all-cause mortality among service members were compared with mortality rates in the U.S. general population ages 15-64 years from 2010 to 2020, utilizing publicly available data sets downloaded from the U.S. Center for Disease Control and Prevention (CDC)’s National Center for Health Statistics National Vital Statistics System.⁶ The only exception was operations of war, which was excluded from the comparison analysis since it is a uniquely military cause of death. Indirect standardization, adjusting for 5-year age category, sex, and racial or ethnic group, was used to calculate standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) using a Poisson distribution. All analyses were performed using SAS^® Enterprise Guide^® software (version 8.3, SAS Inst., Inc., Cary, NC).

Results

From 2010 through 2020, there were 18,251 deaths among 4,956,332 U.S. military service members (Table 1). The mortality rate for all components during the 11-year surveillance period was 75.3 per 100,000 person-years (p-yrs), ranging from 65.4 (in 2019) to 91.8 (in 2011). Mortality rates decreased between 2011 and 2014 for all components, although this trend was more apparent for the active component (Figure 1).

Among all service members, compared to their respective counterparts, all-cause mortality rates were highest among the guard and reserve component (84.8 per 100,000 p-yrs), Army members (93.6 per 100,000 p-yrs), male service members (83.1 per 100,000 p-yrs), non-Hispanic White individuals (81.5 per 100,000 p-yrs), those in the oldest age category of 55 years or older (220.2 per 100,000 p-yrs), and those in combat-related occupations (127.9 per 100,000 p-yrs) (Table 1); it should be noted that serving in a combat-related occupation at time of death does not necessarily mean that a service member died while serving in combat. Among all service members, mortality rates were lowest among the active component (75.3 per 100,000 p-yrs), Coast Guard (48.3 per 100,000 p-yrs), female service members (36.8 per 100,000 p-yrs), Hispanic individuals (57.6 per 100,000 p-yrs), those aged 35-44 years (66.8 per 100,000 p-yrs), and those in other (61.4 per 100,000 p-yrs) and health care (63.1 per 100,000 p-yrs) occupations.

Suicide and self-inflicted injury was the leading cause of death during the surveillance period, accounting for 33% of all service member deaths: 25.1 per 100,000 p-yrs overall, 23.0 per 100,000 p-yrs for the active component, and 28.8 per 100,000 p-yrs for the guard and reserve component (Table 2). Transport accidents and other accidents and adverse events were the second and third, respectively, leading causes of death in service members, accounting for 21% and 12% of all service member deaths, respectively (Table 2). Deaths due to operations of war decreased 91% from 2010 to 2014 (Figure 2a). In contrast, mortality rates due to suicide and self-inflected injury increased 28% from 2010 to 2020. Overall annual trends in mortality rates by cause of death were driven by the trends in male service members (Figure 2b). Female service members had lower, more stable rates compared to male service members (Figure 2c).

The leading cause of death of male service members was suicide and self-inflicted injury (28.2 per 100,000 p-yrs), followed by transport accidents (18.0 per 100,000 p-yrs), and other accidents and adverse effects (10.3 per 100,000 p-yrs) (Table 3). The leading cause of death among female service members was also suicide and self-inflicted injury (10.3 per 100,000 p-yrs), followed by neoplasms (8.1 per 100,000 p-yrs), and transport accidents (7.1 per 100,000 p-yrs) (Table 3).

Compared to the U.S. population, service members had significantly lower rates for all-cause mortality, transport accidents, other accidents and adverse effects, neoplasms, heart disease, and homicide (Table 4). Suicide and self-inflicted injury mortality rates were higher among service members compared to the U.S. population (SMR 1.10, 95% CI 1.08, 1.13). When evaluated by sex, SMR for suicide and self-inflicted injury was 1.08 (95% CI 1.05, 1.11) for male service members and 1.66 (95% CI 1.50, 1.83) for females.

Discussion

This was the first comprehensive MSMR mortality analysis in over a decade, and the first to include National Guard and Reserve members from all branches, including the U.S. Coast Guard. Findings from this report indicate a modestly reduced mortality rate for active component members (69.6 per 100,000 p-yrs) compared to the 1990–2011 mortality rate (75.1 per 100,000 p-yrs).^3-4 The trends in demographic risk factors for all-cause mortality were generally consistent with findings from a recent Millennium Cohort Study mortality analysis of service members and veterans deployed to post-9/11 military operations, which found that mortality rates were higher in National Guard and Reserve members, Army personnel, males, and older individuals, compared to their respective counterparts.⁷

Overall, the leading cause of death for U.S. service members in 2020 was suicide, followed by transport accidents, and then other accidents and adverse effects. These leading 3 conditions were also the leading causes of death for service members during the combined 11-year surveillance period. Among the general U.S. population, ages 17-45 years, in 2020 the leading cause of death was unintentional injury, followed by suicide, heart disease, homicide, and malignant neoplasms.⁸ Service member deaths due to transport accidents decreased from 2010 to 2020, whereas motor vehicle traffic death rates in the U.S. population declined between 2006 and 2010 and increased from 2010 to 2019.⁹

According to prior MSMR reports, the leading causes of death in 2011 among active component service members was operations of war, followed by suicide and transport accidents.^3-4 The decline in operations of war as a leading cause of death in service members was likely influenced by drawdown of U.S. military operations in the U.S. Central Command Area of Operation during the study period. This analysis found higher rates of suicide and transport accidents in 2011, followed by operations of war, as indicated by the data presented in Figures 2a–2c. It is important to note, however, that prior MSMR reports only included deaths occurring while on active duty status, whereas this analysis also included deaths while not in active duty status, which likely accounts for some of the difference.

From 2010 to 2020, suicide was a leading contributor to overall deaths among U.S. service members, accounting for one-third of all deaths. The official source of suicide data in the U.S. Department of War (DOW) is the DSPO Annual Report on Suicide in the Military, which describes, in its most recent (2023) report, a 2013–2020 increasing gradual trend in active component suicide rates, with a decrease in 2021 followed by other increases in 2022 and 2023.¹⁰ Similarly, data in the current study showed a gradual increase in suicide over the study period, with an overall 27.7% increase in suicide rates from 2011 (21.5 per 100,000 p-yrs) to 2020 (28.2 per 100,000 p-yrs) among service members in all components. The same trend was observed in the U.S. population in a report on suicide rates from 2001 to 2021, where the suicide rates from 2010 to 2020 increased during most years.¹¹ The findings of this report are also consistent with a recent U.S. Army mortality surveillance report that identified suicide as the highest cause-specific mortality rate amid a 2014–2019 decline in deaths due to natural causes.¹²

In the 2023 DSPO report, covering a 2011–2023 surveillance period, it was reported that suicide rates among National Guard members were higher than the age- and sex-adjusted U.S. population rates, from 2012 to 2013, and suicide rates were higher among active component members compared to the age and sex adjusted U.S. population in 2020.¹⁰ The current study identified similar findings in sensitivity analyses evaluating adjusted rates by sex, component, and calendar year. This study identified more suicides among service members than reported in the DSPO reports, however, particularly among National Guard and Reserve members. These differences are likely attributed to the use of VA/DOD Mortality Data Repository data to identify deaths, which is not a data source used to identify service member suicide deaths in the DSPO reports. In addition, the AFMES review of deaths that were not initially categorized in 1 of the 26 SEER cause of death categories uncovered more suicide deaths than would have been identified in this report, based on VA/DOD Mortality Data Repository data alone. This emphasizes the importance of comprehensive and integrated death data review.

During the surveillance period, male service members’ suicide mortality rate was more than double that of their female counterparts, a finding that contrasts sharply with the civilian population, where men’s suicide rate is 4 times greater than women’s.¹³ In fact, when compared to an age- and race-adjusted U.S. population, this study found that female service members had a 66% increased rate of suicide, whereas male service members had only an 8% increased rate. This finding does not, however, establish a causal link between military service and suicide risk, as suicide causes could not be determined from available data. This finding does, however, identify women as a specific subpopulation for the DOW to refine and more effectively target future suicide prevention efforts and resources. At least 1 prior study identified higher suicide incidence among active component women ages 17-29 years compared to age-adjusted rates in the U.S. population in 2010, 2012, and 2014.¹⁴ This trend has also been observed in veterans: In the 2025 National Veteran Suicide Prevention Annual Report the suicide rate in 2023 for female veterans was 103.1% higher than for non-veteran female U.S. adults, while the age-adjusted rate for male veterans was 49.7% higher than for non-veteran male U.S. adults.¹⁵

Service members tend to be healthier than the general U.S. population, due to a number of factors including medical screening prior to service accession (disqualifying individuals with significant medical conditions), multiple programs to maintain the health of the force (e.g., physical fitness standards, safety and force health protection programs, no-cost medical services), and frequent attrition (e.g., medical disability) of service members who develop life-threatening medical conditions prior to terminal illness stages.¹⁶ Consequently, it was not surprising that, with the exception of suicide, death rates for conditions evaluated in this study (e.g., neoplasms, heart diseases) were lower for service members than those in the U.S. population, even after adjustments for age, sex, and race and ethnicity. Similarly, although guard and reserve component members are generally required to meet the same physical fitness standards as active duty members, they may test less frequently and face different daily training accountability. Guard and reserve component members may also have less consistent health insurance coverage and less on-base support, which could contribute to the higher mortality rates observed in guard and reserve component members in this analysis.

Limitations of this mortality review include use of NDI records contained in the VA/DOD Mortality Data Repository as the primary source of data for cause and manner of death, with the exception of the uncategorized records (n=1,420) reviewed by AFMES. Previous MSMR reports utilized data maintained by AFMES, which historically collected source documents from civilian jurisdictions on all active duty deaths, which were then validated, coded, and analyzed.⁴ AFMES has since lost that capability; efforts are underway to restore it. The use of a different source of mortality data in this report makes it more challenging to compare these results to the findings of prior reports.

This analysis is intended to provide a survey of recent trends in service member mortality rates, without details of types of intentional or unintentional deaths. It should be noted, however, that use of firearms has consistently been described as the most common method of death in service members who died by suicide, according to annual DSPO reports.¹⁰ Also of note, the Fiscal Year 2024 National Defense Authorization Act (NDAA) (Public Law 118-31) requires an annual report on fatal and non-fatal drug overdoses by members of the U.S. Armed Forces.¹⁷ The most recent NDAA report, released in April 2025, indicates that both fatal and non-fatal overdoses were lower in service members compared to the U.S. population, likely due to frequent, random urinalysis drug testing combined with anti-drug education and outreach. Furthermore, the NDAA report reveals that fatal and non-fatal drug overdoses in service members decreased by more than 40% from 2021 to 2023.¹⁷

The current study was limited to deaths that occurred while in military service; mortality rates for veterans and former service members were not assessed. Deaths were included if they occurred within 90 days after a service member’s last service record, to account for imprecision in military separation dates. Some deaths that occurred shortly after a service member separated from service may have been inadvertently included. This study also did not evaluate multiple or secondary causes of death. Results are dependent upon the accurary of the information record of the underlying cause of death, which can be subjective. When comparing mortality rates with the U.S. population, U.S. population data used the age category of 15-19 years, which is not the same as the military service member age category of 17-19 years, and may have resulted in some residual confounding. In addition, service members could not be excluded from the U.S. population comparison group.

By nature, many military activities are dangerous and sometimes life-threatening. Mortality surveillance is a key component of comprehensive health surveillance among a military population. The findings of this report underscore the importance of suicide prevention programs within the military, with the consideration of the unique risk factors affecting women in service. Further research would be required to better understand why certain subgroups, such as Army soldiers and National Guard members, have higher mortality rates. Continued, detailed mortality surveillance remains essential to identifying emerging threats, evaluating the effectiveness of interventions, and ultimately protecting the health and readiness of the force.

References

Powell KE, Fingerhut LA, Branche CM, Perrotta DM. Deaths due to injury in the military. Am J Prev Med. 2000;18(3 suppl):26-32. doi:10.1016/s0749-3797(99)00172-5
Armed Forces Health Surveillance Center. Motor vehicle-related deaths, active and reserve components, U.S. Armed Forces, 1999–2012. MSMR. 2013;20(11):10-14. https://www.health.mil/reference-center/reports/2013/01/01/medical-surveillance-monthly-report-volume-20-number-11
Armed Forces Health Surveillance Center. Deaths while on active duty in the U.S. Armed Forces, 1990–2011. MSMR. 2012;19(5):2-5. https://www.health.mil/reference-center/reports/2012/01/01/medical-surveillance-monthly-report-volume-19-number-5
Armed Forces Health Surveillance Center. Surveillance snapshot: manner and cause of death, active component, U.S. Armed Forces, 1998–2013. MSMR. 2014;21(10):21. https://www.health.mil/reference-center/reports/2014/01/01/medical-surveillance-monthly-report-volume-21-number-10
National Cancer Institute, National Institutes of Health. Surveillance, Epidemiology, and End Results Program (SEER) Cause of Death Recode. U.S. Dept. of Health and Human Services. Accessed Nov. 11, 2025. https://seer.cancer.gov/codrecode
National Bureau of Economic Research. Mortality Data: Vital Statistics NCHS Multiple Cause of Death Data. Updated Feb. 2023. Accessed Feb. 9, 2024. https://www.nber.org/research/data/mortality-data-vital-statistics-nchs-multiple-cause-death-data
Carey FR, Harbertson J, Sharifian N, Boyko EJ, Rull RP, Millennium Cohort Study Team. All-cause mortality among United States military personnel: findings from the Millennium Cohort Study, 2001–2021. Ann Epidemiol. 2024;99:1-8. doi:10.1016/j.annepidem.2024.08.006
U.S. Centers for Disease Control and Prevention. WISQARS: Web-based Injury Statistics Query and Reporting System. U.S. Dept. of Health and Human Services. Accessed Nov. 11, 2025. https://www.cdc.gov/injury/wisqars/index.html
Spencer MR, Hedegaard H, Garnett M, National Center for Health Statistics. Motor Vehicle Traffic Death Rates, by Sex, Age Group, and Road User Type: United States, 1999-2019. NCHS Data Brief. No. 400. U.S. Centers for Disease Control and Prevention, U.S. Dept. of Health and Human Services. Mar. 2021. Accessed Nov. 11, 2025. https://www.cdc.gov/nchs/data/databriefs/db400-h.pdf
Defense Suicide Prevention Office. Calendar Year 2023 Annual Report on Suicide in the Military: Including the Department of Defense Suicide Event Report (DoDSER). Office of the Under Secretary of Defense for Personnel and Readiness, U.S. Dept. of War. 2024. Accessed Nov. 11, 2025. https://www.dspo.mil/portals/113/2024/documents/annual_report/arsm_cy23_final_508c.pdf
National Center for Health Statistics. Suicide Mortality in the United States, 2001–2021. NCHS Data Brief 2023. No. 464. U.S. Centers for Disease Control and Prevention, U.S. Dept of Health and Human Services. Apr. 2023. Accessed Nov. 11, 2025. https://www.cdc.gov/nchs/data/databriefs/db464.pdf
Kaplansky GF, Toussaint M. U.S. Army mortality surveillance in active duty soldiers, 2014–2019. MSMR. 2024;31(5):2-8. Accessed Nov. 21, 2025. https://www.health.mil/news/articles/2024/05/01/msmr-army-mortality
U.S. Centers for Disease Control and Prevention. Suicide Data and Statistics. U.S. Dept. of Health and Human Services. Updated Mar. 26, 2025. Accessed Nov. 11, 2025. https://www.cdc.gov/suicide/facts/data.html
Reimann CA, Mazuchowski EL. Suicide rates among active duty service members compared with civilian counterparts, 2005-2014. Mil Med. 2018;183(suppl 1):396-402. doi:10.1093/milmed/usx209
U.S. Department of Veterans Affairs. 2025 National Veteran Suicide Prevention Annual Report Part 2 of 2: Report Findings. Accessed February 16, 2026. https://www.mentalhealth.va.gov/docs/data-sheets/2025/2025_national_veteran_suicide_prevention_annual_report_part_2_final.pdf
Office of the Under Secretary of Defense for Personnel and Readiness. DOD Instruction 6130.03 Volume 1. Medical Standards for Military Service: Appointment, Enlistment, or Induction. U.S. Dept. of War. Change 6 Effective Feb. 3, 2026. Accessed Mar. , 2026. https://www.esd.whs.mil/portals/54/documents/dd/issuances/dodi/613003_vol1.pdf?ver=8i9qed7mh4xaa4zossIwza%3d%3d
Defense Health Agency. Fatal drug overdoses in service members significantly below national average. Health.mil. April 16, 2025. Accessed Feb. 16, 2026. https://dha.mil/news/2025/04/16/19/24/fatal-drug-overdoses-in-service-members-significantly-below-national-average

Author Affiliations

Epidemiology and Analysis Branch, Armed Forces Health Surveillance Division, Public Health Directorate, Defense Health Agency, Silver Spring, MD: Dr. Stahlman, Dr. Nieh, Dr. Wells; Armed Forces Medical Examiner System, Dover, DE: Dr. Rupp, Dr. Balcena; Naval Construction Group TWO, Gulfport, MS: Dr. Walsh

Disclaimer

Reportable medical events at Military Health System facilities through week 49, ending December 6, 2025

Sun, 01 Mar 2026 00:00:00 Z

Reportable Medical Events (RMEs) are documented in the Disease Reporting System internet (DRSi) by healthcare providers and public health officials throughout the Military Health System (MHS) for monitoring, controlling, and preventing the occurrence and spread of diseases of public health interest or readiness importance. These reports are reviewed by each service’s public health surveillance hub. The DRSi collects reports on over 70 different RMEs, including infectious and non-infectious conditions, outbreak reports, STI risk surveys, and tuberculosis contact investigation reports. A complete list of RMEs is available in the 2022 Armed Forces Reportable Medical Events Guidelines and Case Definitions.¹ Data reported in these tables are considered provisional and do not represent conclusive evidence until case reports are fully validated.

Total active component cases reported per week are displayed for the top 5 RMEs for the previous year. Each month, the graph is updated with the top 5 RMEs, and is presented with the current month’s (November 2025) top 5 RMEs, which may differ from previous months. COVID-19 is excluded from these graphs due to changes in reporting and case definition updates in 2023.

References

Armed Forces Health Surveillance Division. Armed Forces Reportable Medical Events. Accessed Feb. 28, 2024. https://health.mil/reference-center/publications/2022/11/01/armed-forces-reportable-medical-events-guidelines
Defense Manpower Data Center. Department of Defense Active Duty Military Personnel by Rank/Grade of Service. Accessed Feb. 28, 2024. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports
Defense Manpower Data Center. Armed Forces Strength Figures for January 31, 2023. Accessed Feb. 28, 2024. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports
Navy Medicine. Surveillance and Reporting Tools–DRSI: Disease Reporting System Internet. Accessed Feb. 28, 2024. https://www.med.navy.mil/navy-marine-corps-public-health-center/preventive-medicine/program-and-policy-support/disease-surveillance/drsi

Authors’ Affiliation

Defense Health Agency, Disease Epidemiology Branch, Defense Centers for Public Health–Aberdeen

Department of War and Department of Veterans Affairs strengthen partnership to enhance care for Nation’s warfighters and veterans

Tue, 24 Feb 2026 00:00:00 Z

A long-standing partnership between Irwin Army Community Hospital, Fort Riley, Kansas, and the VA Eastern Kansas Healthcare System is expanding specialty services and access to care for veterans and service members.

On Jan. 14, leaders from both met to discuss strengthening their partnership, in place since 2017, through a new resource-sharing agreement aligning staff, equipment, and specialties to close gaps in access, and advance medical care for warfighters, veterans, and their families. Through their agreement, the health systems align capabilities and specialties for enhanced care to veterans and active duty members, said Col. Laudino Castillo, commander of Irwin Army Community Hospital.

He noted the importance of the partnership given nationwide health care challenges with staffing, available capabilities, and access to specialty care. The key partnership allows them to “align those capabilities (and) align those specialties,” he said, which provides “enhanced care, not only to the veterans, but also to our active duty population — which is required in order to get ready to fight the nation’s wars.”

In 2017, the partnership provided care for more than 3,000 veterans. In 2026, the agreement is expanding access to radiology, optometry, and women’s health. Veterans who once drove to Topeka for imaging or specialty services can now receive many of those services at Fort Riley, saving hours on the road.

Rudy Klopfer, executive director of VA Eastern Kansas Healthcare System, noted that female veterans previously accessed mammography services in the community since medical clinics did not have that capability.

“Our faster-growing population in this area, as well as within the VA, is our female veterans,” Klopfer said. “What a great opportunity for those who have served in the military and now our veterans to come here and receive that service.”

The agreement works both ways. If one system lacks a specialty, the other can help fill the gap. Services such as pulmonology, cardiology, rheumatology, and sleep medicine may be available sooner through shared coordination — providing care for all “who have fought for our freedoms,” Klopfer said.

“Why not capitalize on what this hospital and staff can do for our veterans?” asked Castillo. “At some point, today’s active duty soldiers will be our veterans. Building that relationship now is so valuable for the care we give.”

Leaders emphasized that partnership also sharpen and sustain clinical skills. As providers treat more complex cases, they strengthen readiness and improve care for service members, veterans, and families.

“For me, a partnership is figuring out what we can offer and what they can offer, so we can actually enhance care,” Castillo said. “The bottom line is enhancing care.”

Number of tuberculosis tests and diagnoses of latent tuberculosis infection among U.S. Army active component service members, January 2014–December 2023

Sun, 01 Feb 2026 00:00:00 Z

Abstract

Tuberculosis (TB) remains a force health protection threat to the U.S. military, particularly in crucial populations at increased risk of exposure or re-activation. This analysis examined TB testing trends and the prevalence of latent tuberculosis infection (LTBI) among U.S. Army active component soldiers from 2014 through 2023, the first decade following a major policy shift to targeted testing. Defense Medical Surveillance System data indicate that a total of 339,465 TB tests were administered, primarily (81.0%) tuberculin skin tests. Of those tests, 22,762 (6.7%) were positive, leading to the identification of 18,018 (5.3%) LTBI diagnoses. Asian/Pacific Islander soldiers demonstrated the highest LTBI diagnosis proportion (10.2%), followed by non-Hispanic Black (8.6%), Hispanic (5.6%), and Non-Hispanic White (2.9%) soldiers; the data also include ‘other’ (6.8%) and ‘unknown/missing’ (3.6%) categories. Recruits exhibited a significantly higher LTBI diagnosis proportion (11.0%) than non-recruits (3.6%), highlighting a high prevalence of LTBI among incoming personnel at time of accession. A marked decline in testing volume—a 72% decrease from 2014 to 2023 in the annual numbers of tests administered—followed the 2013 U.S. Army Medical Command policy shift. The substantially higher average proportion (6.7%) of positive tests from 2014 to 2023 compared to the average from the pre-policy era (1.3%) of universal screening demonstrates the successful concentration of testing resources on those most at risk, thereby improving diagnostic yield within a low-prevalence military force. This analysis’s findings describe the epidemiological outcomes of the Army’s targeted testing policy and underscore the importance of ongoing, targeted surveillance to mitigate TB risks in military settings.

What are the new findings?

The 2013 policy that successfully transitioned the U.S. Army from universal tuberculosis screening to a targeted, risk-based strategy reduced testing volume by 72% over the next decade. The decline in tuberculosis testing volume coincided with a substantial increase in diagnostic yield, with the overall positivity proportion rising from 1.3% in the pre-policy era to 6.7% in 2023.

What is the impact on readiness and force health protection?

The 2013 policy revision to a targeted, risk-based tuberculosis testing strategy succeeded in focusing valuable public health resources on high-risk groups. The high prevalence (14.0%) of latent tuberculosis infection that has been identified in recruits confirms that accession is the most critical juncture for tuberculosis control within the Army. Slight but notable differences in testing type positivity suggests opportunity for further policy refinement.

Background

Tuberculosis (TB) remains a significant force health protection concern for the U.S. military, primarily due to the risk of activating latent tuberculosis infection (LTBI) and the potential for transmission in congregate settings.^1,2 A 2014 analysis in MSMR of TB testing in all branches of the U.S. Armed Forces, covering the period from 2004 through 2012, provides a critical baseline for the present analysis. During that era of routine annual screening, the prevalence of LTBI diagnoses was low and stable, ranging from just 0.9% to 1.6% annually among those tested.³ That report provides the context for the current analysis, which focuses on the U.S. Army in the decade following a major policy change.

In November 2013, the U.S. Army Medical Command (MEDCOM) published Regulation 40-64, The Tuberculosis Surveillance and Control Program, which fundamentally altered the Army’s approach to TB control.⁴ This directive shifted the strategy from universal annual testing to a targeted, risk-based testing model, aligning with modern public health principles advocated and then formally updated in May 2019 by the U.S. Centers for Disease Control and Prevention (CDC) and National Tuberculosis Controllers Association (NTCA), which revised sections of previous guidelines. The rationale for this change was to improve screening efficiency and reduce the high number of false positive results when testing large, low-prevalence populations, thereby avoiding unnecessary follow-up procedures and resource expenditures.^4,5

Under the targeted testing policy, routine TB testing is discouraged and is instead mandated only after a formal risk assessment. Key high-risk populations designated for testing include 1) all new recruits upon accession into service, 2) personnel who have deployed or traveled to TB-endemic regions, 3) individuals identified as close contacts of an infectious TB case, and 4) personnel with specific clinical or occupational risk factors, such as health care workers.^2,4 The objective of this analysis was to describe the trends of TB tests and LTBI positivity in Army active component soldiers from January 2014 through December 2023, the first full decade following the implementation of this targeted testing policy, and to compare these findings to the pre-2013 baseline.

Methods

The analysis population included all Army active component soldiers who had a TB test at any military hospital or clinic from January 2014 through December 2023. The data source was the Defense Medical Surveillance System (DMSS). Tests for TB were identified using a combination of immunizations, laboratory, and outpatient procedure data. The DMSS includes data for Army active and reserve component soldier immunizations received during military service and administrative (i.e., billing records) from inpatient and outpatient medical encounters for all Military Health System (MHS) beneficiaries when reimbursed through TRICARE. Laboratory data for interferon gamma release assays (IGRAs), which include QuantiFERONTB Gold Plus (QFT) and T-SPOT. QFT and T-SPOT tests are IGRAs used to detect TB infection; QFT measures overall amount of IFN-γ, or interferon gamma, while T-SPOT counts number of cells producing IFN-γ. TB tests performed during the surveillance period were provided by the Defense Center for Public Health–Portsmouth. All laboratory tests were classified as IGRA. Tuberculin skin tests (TSTs) were identified from immunizations or outpatient procedures, as depicted in Table 1. Outpatient procedures were used to identify additional IGRA tests (Table 1). When calculating the number of tests administered, an individual was counted once per day.

For the purposes of this analysis, a ‘positive’ test was any TST or IGRA test result recorded as “positive” in the database. A diagnosis of LTBI was defined as an individual with a record of a positive TB test who also received a corresponding International Classification of Diseases, 9th or 10th revision, Clinical Modification (ICD-9-CM/ICD-10-CM) code for LTBI (ICD-9-CM: 795.5x; ICD-10-CM: R76.11, Z22.7) (Table 1) in any diagnostic position within 30 days of the test. Demographic information was identified at the time of each test, including beneficiary type, age, sex, race or ethnicity, branch of service, and geographic region of the military treatment facility performing the TB test.

Under the post-2013 targeted testing policy evaluated in this analysis, Army personnel were eligible for TB testing based on a risk assessment.

Results

During the 10-year surveillance period (2014–2023), a total of 339,465 TB tests were administered to U.S. Army active component soldiers. Of these, 22,762 were positive, for an overall positivity proportion of 6.7%. This resulted in 18,018 individuals receiving a diagnosis of LTBI. As shown in Figure 1, the annual number of tests administered declined sharply over the surveillance period, from 82,295 in 2014 to 22,986 in 2023. Concurrently, the proportion of tests returning a positive result nearly doubled, showing a steady increase from 4.5% in 2014 to 8.5% in 2023.

The majority of tests were administered to soldiers who were male (n=270,057, 79.6%), non-Hispanic White (n=167,887, 49.5%), of enlisted rank (n=268,723, 79.2%), and ages 20-34 years (n=235,235, 69.3%). When evaluated by age, soldiers in the under age 20 years category had the highest positivity (8.3%); this age range represents the primary age for accession into the Army. Positivity was 7.3% for both the ages 20-24 and 30-34 years categories, followed by 6.8% for the age 25-29 years category (Table 2).

TST was the most frequently used method (n=274,473), accounting for 81.0% of all tests, while IGRAs (n=64,992) comprised the remaining 19.0% (Table 2).

While men accounted for a larger absolute number of positive tests and LTBI diagnoses, the positivity proportion was nearly identical between men (6.7%) and women (6.9%) (Table 2). Proportions of positive tests and LTBI diagnoses varied notably by racial and ethnic group. Asian/Pacific Islander soldiers had the highest proportions of positive tests (13.0%) and LTBI diagnoses (10.2%), followed by non-Hispanic Black soldiers (11.2% and 8.6%, respectively). In contrast, non-Hispanic White soldiers had the lowest proportions (3.5% and 2.9%, respectively) (Table 2).

A noticeable difference was observed based on recruit status. The proportion of positive tests among recruits was 14.0%, compared to 4.4% among non-recruits (Table 2). The IGRA test showed a slightly higher positivity proportion (7.8%) compared to the TST (6.4%). Enlisted personnel had a higher proportion of positive tests (7.8%) and LTBI diagnoses (6.1%) compared to officers (2.6% and 2.1%, respectively) (Table 2).

Considerable variability in test positivity was observed between military installations (Table 2). Among the 10 installations with highest LTBI test positivity, U.S. Army Garrison (USAG) Bavaria, Germany, which is the largest U.S. Army training area in Europe, comprising Grafenwoehr Tower Barracks and Hohenfels Joint Multinational Readiness Center, reported the highest proportion of positive tests (26.6%) along with USAG Yongsan-Casey in South Korea, with second-highest test positivity (26.4%). Installations that serve as large initial entry training sites, such as Fort Sill, Oklahoma (16.2%) and Fort Jackson, South Carolina (15.4%), also reported high positivity proportions. Conversely, the 10 installations with the lowest positivity for LTBI—Aviano Air Base, Italy; Barksdale Air Force Base (AFB), Louisiana; Dover AFB, Delaware; Ellsworth AFB, South Dakota; Hanscom AFB, Massachusetts; Joint Base Charleston, South Carolina; Keesler AFB, Mississippi; Kirtland AFB, New Mexico; Maxwell AFB, Alabama; and U.S. European Command—each had 0% test positivity (data not shown). This could potentially be due to effective control measures, low local TB prevalence, or even a small sample size.

Discussion

This analysis of over 339,000 TB tests in the U.S. Army active component from 2014 through 2023 shows clear epidemiological outcomes following the 2013 MEDCOM policy⁴ shift to targeted, risk-based screening. These findings should be viewed within the context of the greater U.S., where a diagnosis of active TB disease is relatively uncommon, with a civilian incidence rate (IR) of 2.9 cases per 100,000 persons in 2023.^6,7 This contrasts sharply with the U.S. military, where the risk is substantially lower, with an active TB disease IR estimated at less than 1 case per 100,000 persons.^4,8 Similarly, while a significant reservoir of infection exists in the U.S. general population, with an estimated 4.0% prevalence of LTBI,^6,7 the prevalence among military-age groups is estimated to be only around 1%.^4,8 The primary finding of this analysis is a sharp 72% reduction in the annual number of tests administered. The substantially higher average proportion of positive tests from 2014 to 2023 (6.7%) compared to the average from the pre-policy era of universal screening (1.3%) demonstrates the successful concentration of testing resources on those most at risk, thereby improving diagnostic yield within a low-prevalence military force.

Following the 2013 MEDCOM policy change, the decline in testing volume and corresponding rise in the positivity proportion are the expected and intended results of a successful targeted testing program. By focusing screenings on high-risk populations, such as recruits, personnel deploying to endemic areas, and close personal contacts, the policy effectively eliminated the testing of a large, low-risk population that previously diluted the overall positivity prevalence. The result is not necessarily an increase in overall LTBI within the Army, but rather an improved diagnostic yield and more efficient allocation of public health resources, a finding consistent with the stated goals of the policy.

The demographic and military characteristics associated with LTBI in this analysis are largely consistent with previous reports,^3,5 although the magnitude of these associations is more pronounced due to targeted testing. The elevated proportion of positive tests among recruits (14.0%) underscores that accession screening remains critical for identifying prevalent LTBI acquired prior to service. The disparities observed among racial and ethnic groups, particularly the high proportions among non-Hispanic Black (11.2%) and Asian/Pacific Islander (13.0%) soldiers, are also consistent with national trends.^6,9 These associations are likely confounded, however, by socio-economic factors and, most importantly, country of origin. Non-U.S. birth is a primary LTBI risk factor, and it is probable that this unmeasured variable accounts for a significant portion of the observed differences between racial, ethnic, and even rank categories.^6,10 The higher proportion of LTBI among enlisted personnel compared to officers, for example, is more likely a reflection of underlying demographic differences at accession than of occupational exposures during service.

The pronounced disparities among racial and ethnic groups warrant further consideration, particularly considering this analysis’s limitations. The absence of data on country of birth is a significant confounding variable that likely explains a substantial portion of observed differences. National data consistently show that a majority of TB cases in the U.S. occur in non-U.S. born individuals.⁹ It is highly plausible that the elevated LTBI proportions among Asian /Pacific Islander and non-Hispanic Black soldiers are more reflective of a higher prevalence of non-U.S. birth within those cohorts than of any inherent racial or ethnic predisposition. Future surveillance should aim to integrate country of birth data into the initial screening process, which would enable more precise risk stratification, distinguishing risk acquired prior to service from that acquired during a military career. New country of birth data would allow public health officials to design prevention and treatment strategies more effectively.

From a policy perspective, while the targeted screening strategy has proven successful in enhancing diagnostic yield, these findings highlight the ongoing need for vigilance. The high prevalence of LTBI identified in recruits (14.0%) confirms that the point of accession is the most critical juncture for TB control within the Army. Furthermore, the slight but notable difference in positivity between IGRA (7.8%) and TST (6.4%) tests suggests opportunity for policy refinement; this variance could be attributable to IGRA’s greater specificity, especially among individuals who may have received the Bacille Calmette-Guérin vaccine, or it may reflect its use in more selectively high-risk groups. Given these factors, the Army may consider recommending IGRA as the primary screening tool for specific high-risk recruit populations, such as those born in TB-endemic countries, to further optimize the accuracy and effectiveness of the TB control program.

There are several limitations to this analysis. First, the demographics of the 2 periods (all forces vs. Army), living conditions, and potential exposures in different geographic locations may contribute to some differences. Second, there are generalizability limitations, as results are specific to the U.S. Army active component, limiting the relevance to other MHS beneficiaries such as other service components, family dependents, and retirees. Third, the dataset lacked information on service members’ countries of birth, a crucial unmeasured confounder that, as discussed, likely influenced observed associations with race and ethnicity. Fourth, there are data completeness problems, as the race and ethnicity data had 6% unknown or missing entries, potentially biasing disparity analyses. Fifth, the definition of an LTBI case relied on the presence of an ICD-9-CM/ICD-10-CM code within 30 days of a positive test. This is a significant assumption, as administrative or clinical lapses may lead to misclassification; it is possible that some individuals with a positive test did not receive a corresponding diagnostic code, or vice versa, potentially leading to an under-estimation of the true LTBI burden. Sixth, this analysis assumes uniform implementation of the 2013 MEDCOM policy, but adherence likely varied over time and between installations. This inconsistent application of targeted testing could contribute to the variability in positivity and may have influenced the overall trends. Finally, these are observational data, so causality cannot be determined; external factors, such as changes in deployment patterns or recruitment demographics, may also have influenced the observed trends.

References

Mancuso JD, Tobler SK, Eick AA, Olsen CH. An evaluation of the completeness and accuracy of active tuberculosis reporting in the United States military. Int J Tuberc Lung Dis. 2010;14(10):1310-1315. Accessed Feb. 2, 2026. https://www.ingentaconnect.com/content/iuatld/ijtld/2010/00000014/00000010/art00014;jsessionid=1uqpi287q40iq.x-ic-live-03#supp
Sanchez JL, Hiser MJ. Tuberculosis as a force health protection threat to the United States military. Mil Med. 2015;180(3):276-284. doi:10.7205/milmed-d-14-00433
Armed Forces Health Surveillance Center. Brief report: number of tuberculosis tests and diagnoses of latent tuberculosis infection in active component service members, US Armed Forces, January 2004–December 2014. MSMR. 2014;21(12):8-10. Accessed Feb. 2, 2026. https://www.health.mil/reference-center/reports/2014/01/01/medical-surveillance-monthly-report-volume-21-number-12
U.S. Army Medical Command. MEDCOM Regulation 40-64: The Tuberculosis Surveillance and Control Program. Dept. of the Army, U.S. Dept. of War. Nov. 26, 2013.
Mancuso JD, Tribble D, Mazurek GH, et al. Impact of targeted testing for latent tuberculosis infection using commercially available diagnostics. Clin Infect Dis. 2011;53(3):234-244. doi:10.1093/cid/cir321
U.S. Centers for Disease Control and Prevention. Reported Tuberculosis in the United States, 2023. U.S. Dept. of Health and Human Services. 2024. Accessed Feb. 2, 2026. https://www.cdc.gov/tb-surveillance-report-2023/index.html
Miramontes R, Hill AN, Yelk P, et al. Tuberculosis infection in the United States: estimates from the National Health and Nutrition Examination Survey, 2011–2012. PLoS One. 2015;10(11):e0140881. doi:10.1371/journal.pone.0140881
Defense Health Agency. Weed Army Community Hospital Regulation No. 40-72: Medical Services Tuberculosis Surveillance and Control. Feb. 14, 2025. Accessed Feb. 2, 2026. https://weed-irwin.tricare.mil/portals/148/wach%20regulation%20no.%2040-72%20tuberculosis%20surveillance%20and%20control%202025.pdf
Williams PM, Pratt RH, Walker WL, et al. Tuberculosis: United States, 2023. MMWR Morbid Mortal Wkly Rep. 2024;73(12):265-270. doi:10.15585/mmwr.mm7312a4
Bennett DE, Courval JM, Onorato I, et al. Prevalence of tuberculosis infection in the United States population: the national health and nutrition examination survey, 1999–2000. Am J Respir Crit Care Med. 2008;177(3):348-355. doi:10.1164/rccm.200701-057oc

Author Affiliations

Epidemiology and Disease Surveillance, U.S. Army Public Health Command, West, Joint Base San Antonio–Fort Sam Houston: Dr. Stidham; Army Public Health Nursing, U.S. Army Public Health Command, West: LTC(P) Tyler

Acknowledgments

The authors would like to thank Dr. Sithembile Mabila, Armed Forces Health Surveillance Division, for assistance in obtaining DMSS data.

Disclaimer

The views expressed in this article are those of the authors and do not necessarily reflect the official policy nor position of the Department of the Army, Department of War, nor the U.S. Government.

Title 17, U.S. Code Section 105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S. Code Section 101 defines a U.S. Government work as work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties.

Guest editorial: CHAMPS: the Career History Archival Medical and Personnel System—a summary of career and medical records of the U.S. Armed Forces, 1980–2023

Sun, 01 Feb 2026 00:00:00 Z

Military service requires not only physical but mental as well as moral fitness. To qualify for service, recruits must meet standards in each area, demonstrating their abilities to meet the demands of military service.¹ Maintaining physical and mental fitness is necessary, as continued military career success is contingent on sustained health and fitness. Inability to physically or mentally meet the standards of the U.S. Armed Forces can result in no longer qualifying for service.^2-4

The Career History Archival Medical and Personnel System (CHAMPS) is a comprehensive archival database that collects and maintains career and medical related records for millions of U.S. service members of all branches of service: Army, Navy, Marine Corps, Air Force, Space Force, and Coast Guard. CHAMPS comprises over 1 billion career records from 1980 through 2022, with medical records from 2001 through 2023, for millions of active duty and activated reserve U.S. service members. On average, 212,493 new service members join the military each year (Table). This robust source of data creates a timeline of career and medical events as service members enter, progress through, and separate from service.

The CHAMPS database was created to be a comprehensive, longitudinal database of all career and health events throughout a service member’s military career. CHAMPS can be used to trace the complete trajectory of an individual service member’s career, from accession and occupational specialty to career progression and promotion, deployment history, and eventual separation. Medical history data in CHAMPS include diagnosis and procedure codes, vital and immunization history, and laboratory and radiology records for all inpatient and outpatient encounters within military hospitals and clinics in addition to civilian health care providers.

CHAMPS was designed to provide insight into the correlation between health characteristics and military careers. Thorough analysis of the timing and trajectory of career and health events creates a more robust understanding of the experiences of service members and the complex interplay between career and health in a service member’s life. This editorial presents an overview of the CHAMPS database, including available data fields, sources used, and example questions being answered with CHAMPS data. This editorial is intended to provide a comprehensive understanding of the utility and opportunities for research that CHAMPS presents, its existing and potential collaborations, as well as its significant analytical products to date, in an effort to help answer the most pressing questions about military health, readiness, and career outcomes. This study was approved by the Naval Health Research Center Institutional Review Board in compliance with all applicable federal regulations governing the protection of human subjects (NHRC.2021.002).

Data sources

CHAMPS includes demographic, career, and deployment military data from the Defense Manpower Data Center (DMDC) and health data from the Military Health System (MHS) Data Repository (MDR). Career events comprise 47% of the data in CHAMPS, with the remainder (53%) comprised of medical events (Table). All career and medical events are chronologically concatenated in CHAMPS.

CHAMPS incorporates monthly personnel-and career-related data including demographics, military occupational specialty, accession and separation, deployment start and stop dates, and deployment countries or duty locations from DMDC. Data from a total of 11,748,005 unique service members are housed in the CHAMPS database (Table). Records are uniquely identified using Social Security Numbers (SSNs). Demographic characteristics for each service member include full name, date of birth, SSN, Electronic Data Interchange Personal Identifier (EDI-PI), age, sex, race and ethnicity, education, marital status, and most recent home location prior to military service. Total records in CHAMPS are predominantly Army (42%), followed by Air Force (24%), Navy (21%), Marine Corps (11%), and Coast Guard (2%); Space Force data are still too limited to constitute a significant percentage. On average, from 1980 through 2022, over 80% of accessions are consistently new Army, Air Force, and Navy service members (Figure 1). CHAMPS contains historical medical data from 2001 through 2023, with medical-related information obtained from the MDR on an annual basis. MDR data include medical reimbursement information including dates, locations, and types of encounters; medical codes (e.g., International Classification of Diseases, Current Procedural Terminology, diagnosis-related group); prescriptions for all outpatient care at military hospitals and clinics (i.e., direct care) as well as civilian (i.e., purchased care) facilities; in addition to death date, when applicable, and status. In addition, detailed clinical and administrative data from military hospitals and clinics are available: appointments, referrals, laboratory and radiology orders and results, immunizations, vital records, and both inpatient and outpatient pharmacy records. Civilian care data are limited to health care administrative data billed to TRICARE.

Career-related information in CHAMPS reflects core aspects of a military service career, including promotions, duration of service, and events of significance both individually and historically, as the database spans decades and multiple major conflicts. CHAMPS data include each service member’s initial accession date to the military, rank (e.g., enlisted, E01-E09; officer, O01-O10; warrant officer, W01-W05), branch of service (Army, Navy, Marine Corps, Air Force, Space Force, Coast Guard), status (active duty, activated reserve or Guard), and occupation designator (duty, primary or secondary).

Information on career progression (e.g., promotions, demotions) can be found using rank and branch of service variables. Condition of discharge or reason for separation from the military is categorized and defined as: “dropped from strength or correction” (e.g., desertion, imprisonment, missing in action or prisoner of war, change in status); “entry into officer program” (e.g., officer commissioning, warrant officer program, military service academy); death (e.g., battle casualty, non-battle casualty such as disease, cause of death not specified); administrative separation (e.g., failure to meet behavioral and performance criteria such as character or behavior disorder, drug or alcohol misuse, ineptitude); medical separation (e.g., medical disqualification due to disability, condition existing prior to service, failure to meet weight or body fat standards); early release (e.g., school attendance, insufficient retainability, police duty, seasonal employment, national interest); end of active service (e.g., expiration of term of service due to end of contract without re-enlistment); re-enlistment (if immediate re-enlistment required); and retirement (e.g., service of 20+ years, medical retirement). Military discharge based on conduct and performance are divided into 2 categories: administrative discharge—e.g., honorable, general (under honorable conditions), or other than honorable—and punitive discharge (e.g., bad conduct or dishonorable).

Capabilities, collaborations, and future directions

The CHAMPS database offers numerous research possibilities, given the types, volume, and depth of information it contains. CHAMPS represents a prime opportunity for collaboration and data-driven exploration of the factors that affect not only the career and health outcomes of service members but the complex relationships among those factors. CHAMPS data reveal that some of the principal reasons service members separate from the military are required re-enlistment (37%), end of active service or expiration of term of service (23%), administrative separation or failure to meet behavioral and performance criteria (13%), and retirement (9%) (Table). If including only desired type of discharges—e.g., early release, end of active service, failure to meet behavioral or performance criteria, medical disqualification, retirement—the majority of service members separated because they reached the end of their contracts or chose not to re-enlist (Figure 2). Since early 2000s there has been a notable increase in medical discharges, comparable to a study published by the RAND Corporation.⁵

Career history information in CHAMPS can be compared with available medical information to estimate the relative influence of career- or medical-related factors on service member retention, and other related topics. Numerous medical conditions could be examined in relation to successful military service, to determine their prevalences and corresponding impacts on service member performance. Because CHAMPS passive data collection spans decades, it allows a longitudinal understanding of the relationship between career and health outcomes during time in service.⁶

The inclusion of individual identifiers such as SSNs allows for links with other data sources. Extant military datasets have been augmented with the CHAMPS database to answer pressing questions, resulting in published findings on studies of the impact of injuries on military career outcomes⁷; mortality rates and severe extremity injuries⁸; impacts of traumatic brain injury (TBI) and severe limb injury on suicide⁹; musculoskeletal and blast-induced injuries¹⁰; TBI and low-level blast exposure on adverse career outcomes¹¹; associations between concussion, severe TBIs, and early-onset of dementia¹²; brain injury and military alcohol misuse¹³; the relationship between mental health issues and attrition¹⁴; predictors of psychiatric disorders among combat veterans^15-18; tele-behavioral health, in-person, and hybrid treatment of U.S. service members¹⁹; Marine recruit health and the Recruit Assessment Program^16,20,21; and the limited duty Sailor and Marine Readiness Tracker System.²²

CHAMPS does not track service members (e.g., death records) after separation, as it is limited to data captured during activated reserve or active duty status, but CHAMPS can be linked to data sources that follow health characteristics after service (e.g., Department of Defense and Veterans Affairs Infrastructure for Clinical Intelligence, or DaVINCI).

CHAMPS has been used extensively as a resource at the Naval Health Research Center, both as a named compendium of data and as a program for specific data elements (e.g., DMDC, MDR) that provides expertise and support for data agreement development, links, management, and analysis. All projects utilizing CHAMPS through data sharing agreements are tracked and enumerated. CHAMPS has been utilized for an assessment of the functional outcomes of lumbar microdiscectomy using a standardized physical readiness test (PRT) in a military population; identification of factors associated with PRT failure among U.S. Navy active duty and reserve service members; identification of characteristics of service members assigned to shipboard duty associated with admittance to U.S. Navy Medicine’s temporary limited duty (LIMDU); utilization of event transaction data to investigate post-LIMDU career outcomes for sailors designated for return to duty, in collaboration with Naval Medical Center San Diego; retrospective review of pulmonary medicine patients diagnosed with bronchiectasis and creation of a bronchiectasis registry, generating hypotheses for future research; identification of patients diagnosed with basal cell carcinoma matched with prescription medication history, deployment history, and career history; linking the data of personnel with musculoskeletal injuries sustained during combat; and collaboration with the Department of Defense and Uniformed Services University Brain Tissue Repository to improve warfighter brain health.

CHAMPS is an invaluable resource utilized in a multitude of military health research topics, through the detection of precursor metrics of risk as well as protective factors associated with outcomes such as readiness, individual trajectories, specific health conditions, substance abuse, sexual assault, domestic violence, and suicide. Prior and ongoing projects that have utilized the wealth of longitudinal and individual information housed in the CHAMPS database demonstrate not only its current but continuously expanding capabilities, with significant potential for additional exploration and further collaborations.

References

Office of the Under Secretary of Defense for Personnel and Readiness. DoD Instruction 6130.03, Volume 1: Medical Standards for Military Service: Appointment, Enlistment, or Induction. U.S. Dept. of War. Updated May 28, 2024. Accessed Feb. 1, 2026. https://www.esd.whs.mil/portals/54/documents/dd/issuances/dodi/613003_vol01.pdf
Office of the Under Secretary of Defense for Personnel and Readiness. DoD Instruction 1332.18: Disability Evaluation System. U.S. Dept. of War. Nov. 10, 2022. Accessed Feb. 1, 2026. https://www.esd.whs.mil/portals/54/documents/dd/issuances/dodi/133218e.pdf
Hoge CW, Auchterlonie JL, Milliken CS. Mental health problems, use of mental health services, and attrition from military service after returning from deployment to Iraq or Afghanistan. JAMA. 2006;295(9):1023-1032. doi:10.1001/jama.295.9.1023
Mullinax M, Sorensen I, Dintaman J, Hisle-Gorman E. Effect of serious mental health and physical injuries and their treatment on career trajectories for military service members. Mil Med. 2025;190(11-12):e2466-e2473. doi:10.1093/milmed/usaf191
Simmons MM, Farmer CM, Cherney S, et al. Post 9/11 Trends in Medical Separation and Separation for Service Members with Posttraumatic Stress Disorder and Traumatic Brain Injury. RAND Corporation;2021. Accessed Feb. 1, 2026. https://www.rand.org/pubs/research_briefs/RBA1197-1.html
Gunderson EK, Miller MR, Garland CF, Naval Health Research Center. Career History Archival Medical and Personnel System (CHAMPS): Data Resource for Cancer, Chronic Disease, and Other Epidemiological Research. Report 02-06. Dept. of the Navy, U.S. Dept. of Defense;2002. Accessed Feb. 2, 2026. https://apps.dtic.mil/sti/citations/ADA419547
Trone DW, Villaseñor A, Macera CA. Negative first-term outcomes associated with lower extremity injury during recruit training among female Marine Corps graduates. Mil Med. 2007;172(1):83-89. doi:10.7205/milmed.172.1.83
Schmied EA, Boltz J, Levine JA, et al. All-cause and cause-specific mortality rates after severe extremity injuries among previously deployed active duty service members. PM R. 2023;15(10):1300-1308. doi:10.1002/pmrj.12954
Chung SY, Levine JA, Schmied EA, et al. Impacts of traumatic brain injury and severe limb injury on death by suicide: concurrent investigations using path analysis. J Head Trauma Rehabil. 2025;40(5):e420-e429. doi:10.1097/htr.0000000000001053
Belding JN, Englert R, Bonkowski J, Thomsen CJ. Occupational risk of low-level blast exposure and TBI-related medical diagnoses: a population-based epidemiological investigation (2005-2015). Int J Environ Res Public Health. 2021;18(24):12925. doi:10.3390/ijerph182412925
Belding JN, Bonkowski J, Englert R. Traumatic brain injury and occupational risk of low-level blast exposure on adverse career outcomes: an examination of administrative and medical separations from service (2005-2015). Front Neurol. 2024;15:1389757. doi:10.3389/fneur.2024.1389757
Belding JN, Bonkowski J, Englert R, Grimes Stanfill A, Tsao JW. Associations between concussion and more severe TBIs, mild cognitive impairment, and early-onset dementia among military retirees over 40 years. Front Neurol. 2024;15:1442715. doi:10.3389/fneur.2024.1442715
Woodruff SI, Hurtado SL, Simon-Arndt CM, Lawrenz J. An exploratory case study of environmental factors related to military alcohol misuse. BMC Public Health. 2018;18(1):902. doi:10.1186/s12889-018-5843-5
Schmied EA, Highfill-McRoy RM, Crain JA, Larson GE. Implications of psychiatric comorbidity among combat veterans. Mil Med. 2013;178(10):1051-1058. doi:10.7205/milmed-d-13-00135
Booth-Kewley S, Schmied EA, Highfill-McRoy RM, et al. Predictors of psychiatric disorders in combat veterans. BMC Psychiatry. 2013;13:130. doi:10.1186/1471-244x-13-130
Booth-Kewley S, Highfill-McRoy RM, Larson GE, Garland CF. Psychosocial predictors of military misconduct. J Nerv Ment Dis. 2010;198(2):91-98. doi:10.1097/nmd.0b013e3181cc45e9
Crain JA, Larson GE, Highfill-McRoy RM, Schmied EA. Postcombat outcomes among marines with preexisting mental diagnoses. J Trauma Stress. 2011;24(6):671-679. doi:10.1002/jts.20700
Baker DG, Nash WP, Litz BT, et al. Predictors of risk and resilience for posttraumatic stress disorder among ground combat marines: methods of the Marine Resiliency Study. Prev Chronic Dis. 2012;9:e97. doi:10.5888/pcd9.110134
Walter K, Glassman L, Levine J, et al. Telebehavioral health, in-person, and hybrid modalities of treatment delivery among US service members: a longitudinal observational study. JMIR Ment Health. 2026;13:e83809. doi:10.2196/83809
Larson GE, Booth-Kewley S, Highfill-McRoy RM, Young SY. Prospective analysis of psychiatric risk factors in marines sent to war. Mil Med. 2009;174(7):737-744. doi:10.7205/milmed-d-02-0308
Williams D, Yea JC, Zhu Y, Naval Health Research Center. Summary of Recruit Assessment Program Survey Prediction of Military Personnel Outcomes. Report 21-75. Dept. of the Navy, U.S. Dept. of Defense;2021. Accessed Feb. 1, 2026. https://apps.dtic.mil/sti/citations/AD1158054
McWhorter S, Simon-Arndt C, Carlson L. Overview of Navy Medicine’s limited duty patient population. Mil Med. 2024;189(3-4):820-827. doi:10.1093/milmed/usac348

Author Affiliations

Deployment Health Research Department, Naval Health Research Center, San Diego, CA: Mr. Haile, Mr. Bonkowski, Dr. Khodr, Dr. McAnany, LT Lausted, LT Carnes; Leidos, Inc., San Diego, CA: Mr. Haile, Mr. Bonkowski, Dr. Khodr, Dr. McAnany; Department of Health Professions Education, Uniformed Services University, Bethesda, MD: LCDR Biggs

Acknowledgments

We greatly acknowledge the support of an additional data management team member of the Career History Archival Medical and Personnel System (CHAMPS): Khider Allos, MCS, BSc. We also thank all current and previous members of the CHAMPS data management team for maintaining this important archival database since its inception.

Disclaimer

The views expressed in this article are those of the authors and do not necessarily reflect official policy or position of the Department of the Navy, Department of Defense, nor the U.S. Government.

LCDR Biggs, LT Lausted and LT Carnes are military service members. This work was prepared as part of their official duties. Title 17, U.S. Code Section 105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S. Code Section 101 defines a U.S. Government work as work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties.

The authors declare that they have no competing interests.

Report 25-70 was supported by the Office of Naval Research under work unit NMR11355-29. The study protocol was approved by the Naval Health Research Center Institutional Review Board in compliance with all applicable federal regulations governing the protection of human subjects. Research data were derived from approved Naval Health Research Center Institutional Review Board protocol NHRC.2021.002.

The datasets generated and analyzed during the current study are not publicly available due to personally identifiable information regulations, but they may be made available by the corresponding author on reasonable request and approval by the Naval Health Research Center Institutional Review Board/Privacy Office.

Surveillance snapshot: Adherence to disease and injury standardized surveillance categories in two U.S. Africa command exercises, 2024

Sun, 01 Feb 2026 00:00:00 Z

Disease and non-battle injury (DNBI) is a significant threat to military operations, historically exceeding combat injuries in deployed settings.^1-4 Disease and injury (D&I) surveillance supports health risk assessment for the purpose of instituting interventions as needed to promote and maintain the health of deployed forces.^5-7 Defense Health Agency Procedural Instruction (DHA-PI) 6490.03: Deployment Health, effective June 19, 2019, defines standardized surveillance categories for D&I reporting.⁶ While U.S. Department of War (DOW) policy prescribes electronic systems such as the Disease Reporting System internet (DRSi) and ESSENCE,⁶ the austere nature of expeditionary operations often necessitates reliance on paper documentation, where adherence to these guidelines has not been described.

D&I data from 2 exercises, African Lion and Flintlock, held in the U.S. Africa Command (USAFRICOM) Area of Responsibility (AOR) in 2024 were evaluated. The absolute and relative D&I burden from each exercise was calculated and compared with DHA-PI 6490.03 for category consistency and standardization. De-identified D&I surveillance data were obtained from the AFRICOM Surgeon’s Office, Southern European Task Force–Africa, and Special Operations Command–Africa. D&I entries were submitted by field medical teams—comprising Guard and active duty physicians, nurse practitioners, physician assistants, and combat medics—in accordance with exercise-specific reporting requirements, primarily using paper logs and consolidated after-action reports. The project was reviewed and approved by the Institutional Review Board of the Uniformed Services University of the Health Sciences.

During the African Lion 2024 exercise (33 days), 314 D&I cases were reported within 13 categories (Table). Only 8 of the 13 categories (61.5%) and 155 cases (49.4%) conformed to standardized surveillance guidelines in accordance with DHA-PI 6490.03. The Flintlock 2024 exercise (12 days) recorded 203 D&I events within 18 categories. Compared to the DHA-PI 6409.09 standardized categories, 7 of 18 categorizations (38.9%) and 113 D&I cases (55.7%) were recorded correctly. While the high relative burden of respiratory (upper) cases (23.2%) in African Lion and gastrointestinal cases (30.0%) in Flintlock suggest significant environmental threats, the use of standardized surveillance categories in only 49.4% and 55.7% of entries, respectively, limits the ability to meaningfully correlate these events with health risk assessments or location-specific risk mitigation.

This descriptive analysis demonstrated inconsistent adherence of D&I surveillance to published military guidelines. Reporting and categorization of D&I during these exercises highlights the need for enhancing technical and administrative readiness in austere, resource-limited operational environments. While DOW electronic health records (e.g., Theater Medical Data Store) are designed to feed into standardized reporting systems, use of paper documentation in these austere environments prevents this automation.

Accurate documentation is needed for actionable medical readiness and planning.^1,5 Furthermore, lack of adherence to standardized case definitions at the point of care limits the operational value of surveillance; a list of illnesses and injuries without proper classification is ineffective for ensuring force health protection. Even in austere environments, and perhaps especially in those environments, standardized and timely data are essential for early threat detection and operational decision-making.

Recommended courses of action to combatant commands include prioritization of efforts to improve D&I surveillance by incorporating surveillance strategy into operational plans and orders (Annex Q); modifying field documentation tools (e.g., Standard Form 600, Chronological Record of Medical Care) to include D&I checkboxes; and integrating preventive medicine assets to provide just-in-time training and data quality assurance.

References

Alcover KC, Howard K, Poltavskiy E, et al. Disease and non-battle injury in deployed military: a systematic review and meta-analysis. Mil Med. 2024;189(s3):21-30. doi:10.1093/milmed/usae033
Belmont PJ, Goodman GP, Waterman B, et al. Disease and nonbattle injuries sustained by a U.S. Army brigade combat team during Operation Iraqi Freedom. Mil Med. 2010;175(7):469-476. doi:10.7205/milmed-d-10-00041
Hauret KG, Pacha L, Taylor BJ, Jones BH. Surveillance of disease and nonbattle injuries during US Army operations in Afghanistan and Iraq. US Army Med Dep J. 2016:(2-16):15-23.
Kauvar DS, Gurney J. Exploring nonbattle injury in the deployed military environment using the Department of Defense Trauma Registry. Mil Med. 2020;185(7/8):e1073-e1076. doi:10.1093/milmed/usz481
Armed Forces Health Surveillance Branch. Absolute and relative morbidity burdens attributable to various illnesses and injuries among active component members of the U.S. Armed Forces, 2023. MSMR. 2024;31(6):2-10. Accessed Feb. 2, 2026. https://www.health.mil/news/articles/2024/06/01/msmr-health-care-burden-active-component
Office of the Under Secretary of Defense for Personnel and Readiness. DoD Instruction 6490.03: Deployment Health. U.S. Dept. of War. Jun. 19, 2019. Accessed Feb. 2, 2026. https://www.esd.whs.mil/portals/54/documents/dd/issuances/dodi/649003p.pdf
Chairman of the Joint Chiefs of Staff. Joint Publication 4-02: Joint Health Services, Incorporating Change 1, 28 September 2018. Accessed Feb. 2, 2026. https://cdmrp.health.mil/pubs/pdf/joint%20health%20services%20publication%20jp%204-02.pdf

Author Affiliations

School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD: Lt Col Rupert; Office of the Command Surgeon, U.S. Africa Command, U.S. Department of War: Lt Col Frankel, Ms. Dressner; Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences: Lt Col Sayers

Disclaimer

The views expressed are those of the authors and do not necessarily reflect the official view nor policy of the Uniformed Services University of the Health Sciences, U.S. Air Force, nor the Department of War. This work was prepared by military and civilian employees of the U.S. Government as part of their official duties and therefore is in the public domain and does not possess copyright protection. Title 17, U.S. Code Section 105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S. Code Section 101 defines a U.S. Government work as work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties.

Public domain information may be freely distributed and copied, but as a courtesy it is requested that the Uniformed Services University and authors be given appropriate acknowledgment.

The authors have no conflicts of interest to disclose.

Historical perspective: Post-infection symptoms in U.S. soldiers with malaria during the Second World War: major limitation to return to duty

Sun, 01 Feb 2026 00:00:00 Z

Abstract

Malaria proved decisive in determining the outcome of the Pacific theater during the Second World War. In 1943 alone, over 100,000 malaria cases were reported among the U.S. military in the Southwest Pacific and South Pacific. Thousands of sick soldiers were evacuated from their units and hospitalized for weeks or months of rehabilitation due to malaria. The primary challenge was not treatment of acute infections, as death rates were very low, but rather an inability to return recovered soldiers quickly to their units. Relapsing Plasmodium vivax malaria posed a particular problem, with many soldiers stationed at Guadalcanal or New Guinea suffering more than 10 relapses. Secondary gain from residual symptoms became apparent when around 1% of malaria patients were repatriated for ‘chronic malaria’. Future conflicts disrupted by infectious diseases will almost certainly include diffuse, post-infection symptoms that must be anticipated to prevent catastrophic warfighter attrition.

“However, the way the individual adjusted to the malaria and concurrent situational factors, contributed to the development of symptoms, to their perpetuation and intensification.”¹

Nearly all U.S. soldiers deployed to the Pacific theater during the Second World War were hospitalized at least once per year,² primarily for infectious diseases—such as malaria, scrub typhus, filariasis, and skin infections—rather than combat wounds.³ Malaria came close to being a decisive agent in the Pacific theater due to the sheer number of casualties it produced. Infection rates reached 250 per 1,000 men per year in the Solomon Islands and New Guinea.⁴ Figure 1 shows the variety of hospitalizations in Guadalcanal, in the Solomon Islands, in 1942-1943, with a majority due to malaria.³ At the end of 1942, entire units had been incapacitated by malaria in Milne Bay, New Guinea due to inadequate chemoprophylaxis and preventive measures, but fortunately after the combined Australian and U.S. forces had already defeated the Japanese invasion the previous August.⁵

From the viewpoint of military commanders, the most critical limitation of malaria infection was that infantry divisions withdrawn from the Solomon Islands or New Guinea became useless for further deployment for at least 6 months.⁴ Multiple relapses of malaria struck soldiers even while their divisions attempted to reconstitute in non-endemic areas such as Australia and Fiji. Military planners estimated that maintaining contact with the enemy by 1 division required at least 3, possibly as many as 5, divisions simply because of malaria casualties.^5,6 Relapsing malaria due to Plasmodium vivax was a common sequela that often led to multiple, sequential febrile attacks even when a soldier was removed from an endemic area.⁷

Two weeks of anti-malarial drug treatment was required for those sick enough to be hospitalized. Many soldiers were medically evacuated from combat zones due to limited medical support in forward areas.⁸ By 1943, the situation had become unsustainable. Eventually, improved regimens of enforced chemo-suppression with quinacrine, combined with better anti-mosquito measures, reduced new infections, and treatment regimens were shortened to 7 days. Use of 8-aminoquinolines to eliminate latent parasites causing relapse would have to wait for chemotherapeutic advances during the Korean War, however.⁹

While treatment with quinine and quinacrine (atabrine) proved successful, and death rates remained very low,⁶ a more insidious problem for the U.S. military emerged. Large numbers of soldiers developed chronic symptoms and weight loss that led to repatriation for ‘chronic malaria’. Chronic malaria was characterized not only by multiple relapses—10 were not unusual—but a failure to recover between nearly monthly febrile relapses. Soldiers suffering from chronic malaria populated a medical system designed to treat combat injuries, with 3,334 malaria evacuations to the U.S. from the South Pacific in 1943, and a similar number from the Southwest Pacific to Australia.^3,8

The magnitude of the problem prompted the U.S. military to designate entire Army general hospitals as specialty centers for tropical diseases: in Longview, Texas; Modesto, California; Swannanoa, North Carolina; and in Klamath Falls, Oregon, for the U.S. Navy and Marine Corps; in addition to the 105th General Hospital in Gatton, Australia.⁴ Those dedicated facilities were clearly preferrable to the tented field hospitals (Figure 2). The farther a malaria-infected soldier traveled from where he acquired infection, the better the treatment facilities became—and more removed the opportunity to return to his original unit. Secondary gains from continued symptoms increased proportionally. The concern over chronic malaria grew so severe that medical studies were initiated in both Australia and Fiji to determine better ways to limit disease casualties. After studying 3,358 malaria patients in Australia in 1943-1944, officials found a wide range of responses to malaria infection among service members.⁸ Many soldiers reported chronic weakness and a variety of ill-defined complaints including headaches, dizziness, nervousness, insomnia and tremor. In Fiji, largely working with soldiers from the Americal (23rd) Infantry Division, a group of psychiatrists conducted a medical and laboratory study of malaria groups at the 18th General Hospital,¹ and found similarly wide variation in soldiers’ abilities to deal with malaria infection. Those who tolerated the disease poorly primarily reported weakness and chronic fatigue, along with a host of ancillary complaints. Remarkably, the only definite physical finding from the studies of malaria casualties was that most soldiers had lost 10-20 pounds of body weight since developing malaria.

The results of those wartime studies concluded that the non-physical effects of malaria were largely psychosomatic in nature. It was ultimately determined that patients—and the U.S. Army—achieved better outcomes when chronic malaria’s psychosomatic element was recognized and its medicalization was minimized.⁸ One wartime study author observed, “The soldier is usually capable of remaining useful, even though sometimes in a limited capacity, so long as his morale remains satisfactory; and symptomatology only becomes severe when the adjustment of the person is faulty.”¹ Although malaria infection was nearly universal for frontline infantry, the vast majority of soldiers coped well with the stress and only required hospitalization when overcome by 40° Celsius fevers and uncontrollable rigors.

Neuropsychiatric casualties due to maladjustment were not new in the Pacific theatre. All humans have limitations on abilities to cope with stress, and soldiers in the Pacific theater found themselves in life-threatening situations in a tropical jungle, with malaria an added stress in an austere warfare environment. Soldiers whose coping mechanisms failed early showed up as combat stress casualties. In mid-1943, after landing on New Georgia in the Solomon Islands, the 43rd Division had been incapacitated by war neurosis and combat stress resulting in 16% medical evacuations.¹⁰ Fully 15% of medical evacuations from the South Pacific in 1943 were due to neuropsychiatric diagnoses, with likely considerable overlap with other diseases such as malaria.³

Chronic malaria manifested later in the World War II Pacific conflict, when soldiers consciously or unconsciously understood that illness would keep them from returning to a combat zone. Medicalizing the symptoms of either combat stress or malaria was counter-productive and likely extended soldier hospitalizations during the war. The treatment of combat stress casualties was subsequently developed with emphasis on proximity, immediacy, and expectancy—principles that greatly influenced recommendations for handling post-infection casualties. Malaria treatment units were created near the front lines and evacuation distances were minimized. These strategies conformed to the principles of combat stress treatment and succeeded even when the U.S. Army encountered drug-resistant malaria during the Vietnam War, proving highly effective for management of post-infection casualties.¹¹

While malaria is unlikely to recur as a major casualty-producing agent in current South China Sea scenarios, the recent COVID-19 pandemic demonstrated both our limited ability to predict future epidemics and the potency of chronic disabling conditions such as the poorly defined ‘long COVID’.¹² Current INDOPACOM (Indo-Pacific Command) military exercises can expose service members to scrub typhus, also likely to have post-infection symptoms, given its potential for cardiovascular damage.¹³ Most infectious diseases have post-infection symptoms, seen during World War II, with filariasis, and during the Vietnam conflict, with dengue infections.^14,15

Given the ability of disinformation to spread via the internet, along with the expectation of many soldiers that infections will cause chronic symptoms, future military medical officers will almost certainly find themselves in situations analogous to those in the South Pacific in 1943. Applying the same treatment principles established for combat stress neuropsychiatry—namely proximity, immediacy, and expectancy—for infectious diseases is likely to be successful in minimizing preventable casualties during any future conflict.

References

Tumulty PA, Nichols E, Singewald ML, Lidz T. An investigation of the effects of recurrent malaria: an organic and psychological analysis of 50 soldiers. Medicine (Baltimore). 1946;25:17-75. doi:10.1097/00005792-194602000-00002
Thomas HM. Southwest Pacific area. In: Medical Dept., U.S. Army; Coates JB, ed. Internal Medicine in World War II, Volume I: Activities of Medical Consultants. Office of the Surgeon General, Dept. of the Army;1961:473-568. Accessed Feb. 2, 2026. https://apps.dtic.mil/sti/tr/pdf/ada286772.pdf
Baker BM. South Pacific area. In: Medical Dept., U.S. Army; Coates JB, ed. Internal Medicine in World War II, Volume I: Activities of Medical Consultants. Office of the Surgeon General, Dept. of the Army;1961:569-623. Accessed Feb. 2, 2026. https://apps.dtic.mil/sti/tr/pdf/ADA286772.pdf
Hoff EC. Malaria. In: Medical Dept., U.S. Army; Coates JB, ed. Preventive Medicine in World War II, Volume VI: Communicable Diseases. Office of the Surgeon General, Dept. of the Army;1963.
Walker AS. The Island Campaigns (Volume III). In: Australia in the War of 1939–1945, Series Five: Medical. Australian War Memorial;1957. Accessed Feb. 2, 2026. https://www.awm.gov.au/collection/C1417326
Joy RJ. Malaria in American troops in the south and southwest Pacific in World War II. Med Hist. 1999;43:192-207. doi:10.1017/s002572730006508x
Shanks GD. Plasmodium vivax relapse rates in Allied soldiers during the Second World War: importance of hypnozoite burden. Am J Trop Med Hyg. 2022;107:1173-1177. doi:10.4269/ajtmh.22-0546
Levine HD. Medical experiences with American troops in the Pacific: with remarks on the diagnostic value of sternal puncture in malaria and on the innocuousness of hookworm infection. NEJM. 1946;235:933-938. doi:10.1056/nejm194612262352604
Zottig VE, Shanks GD. Historical perspective: the evolution of post-exposure prophylaxis for vivax malaria since the Korean War. MSMR. 2021;28(2):8-10. Accessed Feb. 2, 2026. https://www.health.mil/reference-center/reports/2021/02/01/medical-surveillance-monthly-report-volume-28-number-02
Hallam FT. War neuroses. Appendix G. In: Mullins W, ed. Neuropsychiatry in World War II, Volume II: Overseas Theaters. Office of the Surgeon General, Dept. of the Army;1973:1063-1069. Accessed Feb. 2, 2026. https://collections.nlm.nih.gov/catalog/nlm:nlmuid-0211560X2-mvpart
Modell W. Malaria and victory in Vietnam: the first battle against-drug-resistant malignant malaria is described. Science. 1968;162:1346-1352. doi:10.1126/science.162.3860.1346
Hitchcock S, Cintron SA, Kasuske L, Diaz FJ, Pierce J. Post-COVID-19 condition in military personnel. Mil Med. 2024;189:e1277-e1281. doi:10.1093/milmed/usad453
Suhr R, Belonogoff S, McCallum F, Smith J, Shanks GD. Scrub typhus outbreak among soldiers in coastal training area, Australia, 2022. Emerg Infect Dis. 2024;30:41-46. doi:10.3201/eid3014.240056
Russell PK, Ognibene AJ. Dengue and dengue shock syndrome. In: Ognibene AJ, ed. Internal Medicine in Vietnam, Volume II: General Medicine and Infectious Diseases. Office of the Surgeon General, Dept. of the Army;1982:91-98. Accessed Feb. 2, 2026. https://achh.army.mil/history/book-vietnam-genmedvn-ch05
Shanks GD, Smith JK. Lymphatic filariasis in soldiers exposed in INDOPACOM. MSMR. 2024;31(8):20-23. Accessed Feb. 2, 2026. https://www.health.mil/news/articles/2024/08/01/msmr-filariasis-indopacom
WW2 Military Hospitals: Pacific Theater of Operations and Minor Theaters. WW2 Medical Research Centre. 2024. Accessed Feb. 2, 2026. https://www.med-dept.com/articles/ww2-military-hospitals-pacific-theater-of-operations

Author Affiliations

Australian Defence Force Infectious Disease and Malaria Institute, Enoggera, Queensland, Australia; School of Public Health, University of Queensland, Brisbane, Australia

Acknowledgments

The author acknowledges the service and sacrifice of all those who served in the U.S. military during World War II and thanks the many unnamed military officers, scientists, historians, and medical librarians who unselfishly provided data and ideas for this manuscript, especially the librarians at the Australian Defence Force Library at Gallipoli Barracks, Queensland.

Disclaimer

The opinions expressed are those of the author and do not necessarily reflect those of the Australian Defence Force nor the Department of Foreign Affairs and Trade.

No specific funding was given for this work.

The author does not claim any conflicts of interest.

Reportable medical events at Military Health System facilities through week 44, ending November 1, 2025

Sun, 01 Feb 2026 00:00:00 Z

Total active component cases reported per week are displayed for the top 5 RMEs for the previous year. Each month, the graph is updated with the top 5 RMEs, and is presented with the current month’s (October 2025) top 5 RMEs, which may differ from previous months. COVID-19 is excluded from these graphs due to changes in reporting and case definition updates in 2023.

References

Armed Forces Health Surveillance Division. Armed Forces Reportable Medical Events. U.S. Dept. of War. Accessed Feb. 28, 2024. https://health.mil/reference-center/publications/2022/11/01/armed-forces-reportable-medical-events-guidelines
Defense Manpower Data Center. Department of Defense Active Duty Military Personnel by Rank / Grade of Service. U.S. Dept. of War. Accessed Feb. 28, 2024. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports
Defense Manpower Data Center. Armed Forces Strength Figures for January 31, 2023. U.S. Dept. of War. Accessed Feb. 28, 2024. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports
Navy Medicine. Surveillance and Reporting Tools–DRSI: Disease Reporting System Internet. U.S. Dept. of War. Accessed Feb. 28, 2024. https://www.med.navy.mil/navy-marine-corps-public-health-center/preventive-medicine/program-and-policy-support/disease-surveillance/drsi

Authors’ Affiliation

Defense Health Agency, Disease Epidemiology Branch, Defense Centers for Public Health–Aberdeen

U.S. Navy veteran and VA health care executive appointed as Department of War’s top medical leader

Mon, 12 Jan 2026 00:00:00 Z

Keith Bass, a retired U.S. Navy commander and career health care leader dedicated to delivering health services to active duty military and veterans, was sworn in Jan. 12, 2026, as the assistant secretary of war for health affairs.

Bass succeeds Dr. Lester Martinez-López, who held the position 2022-2024. Dr. Stephen L. Ferrara has been serving as the acting assistant secretary since January 2025 and will now serve as principal deputy assistant secretary of war for health affairs.

“It is the highest honor and a profound privilege to be entrusted with the health and well-being of our Nation's warfighters and their families,” said Bass, who was confirmed by the Senate on Jan. 5, 2026. “I am deeply committed to delivering the best health care possible and to continue in service to those who serve.”

As the former medical center director for West Texas VA Health Care System, Veterans Integrated Service Network 17, Bass managed health care services for more than 24,000 veterans, an operating budget of $153 million, and thousands of employees. He brings a decades-long career of overseeing comprehensive health care systems across government, the military, and the public.

During his career, Bass became the CIA’s first nonphysician director of the Office of Medical Services, leading teams of hundreds of physicians, nurses, physician assistants, and clinical psychologists who delivered health care to the agency’s workforce.

As a former director of the White House Medical Unit, he managed medical care to the president, the vice president, and their families. Before his position at the Department of Veterans Affairs, Bass was the senior vice president at GlobalMed, managing virtual patient care programs and telehealth services for agencies including the VA, Department of War, Defense Health Agency, and the White House.

Bass said he will leverage his comprehensive, interagency leadership experience to champion exceptional health care to warfighters and families he will serve.

“I am deeply committed to forging a seamless, world-class healthcare experience that supports our uniformed personnel and their families from their first day of service to their last, and continues to care for them as veterans,” he said. “Our warfighters and families deserve nothing less than the absolute best.”

Bass earned undergraduate degrees in psychology and rehabilitation science from Arkansas Tech University, and a master’s of science in rehabilitation counseling from University of Arkansas. He also holds a master’s in business administration and master’s of health care administration from Texas Women’s University, and a graduate certificate in legislative affairs from Georgetown University.

Top DOW doctor: ‘Fundamentally, our focus is to support the warfighter’

Mon, 12 Jan 2026 00:00:00 Z

Supporting the warfighter, sustaining medical skills, and strengthening the health care system are three key pillars of providing “health care for the people who defend our country,” says the top Department of War doctor.

Dr. Stephen Ferrara, an experienced clinician, combat veteran, educator, and health care leader, recently reflected on the pivotal work of the Military Health System in 2025, which delivered visible gains in readiness-focused partnerships, increased productivity, revamped credentialing and privileging process, and early deployments of artificial intelligence tools to give clinicians more time with patients.

On Jan. 20, 2025, Ferrara was appointed as the principal deputy assistant secretary of war for health affairs and immediately stepped in as the acting assistant secretary for health affairs until the official nominee, Keith Bass, was confirmed by the Senate Jan. 5, 2026.

Bass has now assumed duties as the assistant secretary.

Ferrara is a retired U.S. Navy doctor with 25 years on active duty and remains a practicing physician. Prior to rejoining the DOW, he was the Chief Medical Officer at the CIA. He also served as the deputy director for clinical operations for the National Capital Region, the DOW’s largest health care network. He currently serves as an interventional radiologist at Walter Reed National Military Medical Center and is a clinical professor of radiology and radiological sciences at the Uniformed Services University of the Health Sciences.

In this interview, Ferrara discussed the critical priorities for the MHS, such as upgrading infrastructure, maintaining clinical readiness, and strengthening the pipeline of talented professionals dedicated to delivering the best possible care for warfighters.

Following are edited excerpts from the interview, which can be viewed in its entirety on www.health.mil:

Question: You often talk about the “3 S’s” for the Military Health System: supporting the warfighter, sustaining our skills, and strengthening our chain. What do they mean?

Ferrara: Those principles underpin our mission: support the warfighter. We provide health care to the people who defend our country, and that's what makes us unique as a health care system. There are many great health care systems in America — but there's only one great American health care system that goes to war. Fundamentally, our focus is to support the warfighter.

Sustaining our skills means our learned skills must be maintained. I liken it to how our aviators have to get flight hours or how the trigger-pullers go to the range. For our health care professionals, it's working in our MTFs (military treatment facilities) where we're taking care of patients and keeping sharp. We have to be great because our warfighters deserve our very best.

On strengthening our chain: We stand on the shoulders of many great people, both in the military and in military medicine — so it's on all of us to make sure that we pass along that wisdom. Our MTFs are a giant force-generation platform. We graduate 16,000 medical technologists with a variety of skill sets every single year. If we were a university, we'd be the biggest one. We have graduate medical education programs. We have nursing training programs across our entire enterprise. We are always training people to be able to take that baton from us and continue to be a world-class health care system.

Question: It's been an action-packed year when you look back at 2025. How would you characterize a few of our greatest successes?

Ferrara: First of all, we perform on the big picture with great success, including increasing our partnerships. I think we've done a lot to bring in more patients, higher-complexity patients, which improves our force-generation and our skill-sustainment platforms. We've brought in more Medicare patients, and we’re really happy to be able to take care of them. Similarly, with the Department of Veterans Affairs, we've strengthened our partnership to take care of America’s veterans.

We've made significant efforts to reduce administrative burden and improve quality of life. I'm very sensitive to the burdens we place on those who care for patients, because that's what they love to do. We now have universal privileging, which is a significant breakthrough, as it eliminates low-value administrative work such as renewing privileges or obtaining transfer briefs. If you're good enough to work at one MTF, you can work across the enterprise. It also helps our mission by increasing agility, capacity, and capability by giving us the ability to utilize our personnel where and when we need them.

We rolled out ambient listening, an artificial intelligence-powered tool to help bring humanity back to health care. There’s the burden of how much note writing providers have to do, where people are taking work home. With this new tool, you can have a nice, captured conversation with your patient, talk to them, and really be focused and centered on the patient. Ambient listening rolled out at four sites this fall and we're looking to distribute that across the enterprise in 2026.

Question: Speaking about AI in a broader context, are there other priorities that you've set for the MHS to incorporate that technology?

Ferrara: We’re in a golden moment for medicine in terms of all the technology occurring, and AI is a big element of that. AI can also accelerate personalized medicine with the molecular and genetic techniques that we have. For drug discovery and development, AI can enable better therapies for patients.

Clinicians can use AI to make more rapid diagnoses and more rapid treatments, and technologies to empower and enable those frontline medics and corpsmen to be able to do prolonged field care. We’re leaning into our forward-deployable technology platforms, using tools enabling medics and corpsmen right at the point of injury to begin documenting the service member’s medical record. To support clinical decision-making, technology can provide access immediately to guide care for those service members, so we can maximize survivability in the war fight.

Question: You spent a significant amount of time this year going to the deck plate and visiting MTFs around the world. What are your biggest takeaways from those visits, and have you had the chance to incorporate any of the feedback that you've learned when you've been on the ground?

Ferrara: It's always really energizing and restorative for me to get out to the field and see where the work is done. I try to meet as many staff as I can, whether I'm in the operational unit or at an MTF. One of the things I share with them is why it's so important for me to go to the field. Here at the Pentagon, we’re making a lot of decisions, but we have such a large and complex health care system … sometimes the nature of the information gets heavily filtered by the time it gets to me.

When I go to those places, I can learn what it's like to be there. I don't think people at our MTFs or operational units are a mere row in an Excel spreadsheet. There's a lot more to it than that. These are people who are taking care of patients. It's really helpful for me to hear their stories, and I learn a lot from them. Whether it’s simple or about policy, I come back with a punch list of things to help fix.

Question: Can you talk a little bit about what happened at Walter Reed National Military Medical Center earlier in January 2025, one of your first experiences as acting assistant secretary?

Ferrara: Walter Reed, the President's hospital, experienced facility challenges including flooding. Like many of our facilities, they have aging infrastructure and deferred maintenance. I compliment their staff for moving heaven and earth to ensure they always took care of their patients. I went out there and walked the spaces, and then was able to go right to Congress and say, “here are the infrastructure problems, and we need support.” In the One Big, Beautiful Bill Act, they gave us $2 billion specifically because of those efforts. We can apply it to help close some of the gaps at our facilities with the greatest challenges for infrastructure. I think we came out of it really well, and that's where that kind of advocacy on the Hill can be invaluable.

Question: What are some of the biggest resource-related challenges and successes for the MHS right now?

Ferrara: I'm a people-oriented leader — I believe having not only the right number of people but also the right skill types and in the right places — because health care is a very personal craft that we do.

We faced challenges early in the year with our civilian teammates as we sought to preserve many positions, but we were very successful because we were able to show how valuable everyone on our team is.

In the last several months of the fiscal year, we implemented policies and increased revenue collections by about $700 million. That's really exciting, because we can take those resources and we can use them to hire people, work on infrastructure, and focus on things that we need.

The National Defense Authorization Act (Fiscal Year 2026) was passed, and we're getting a top-line increase as a department. I'm looking forward to more financial resources that we can then deploy to improve health care for our warfighters and beneficiaries.

Question: What’s the value of welcoming TRICARE For Life beneficiaries back into certain MTFs for patients and for providers?

Ferrara: First and foremost, we're a military family. The opportunity to welcome our TRICARE For Life patients, our seniors, back into the MTFs where they want to get their care is the right thing to do, because it's bringing people in who want to get care from us. They trust us. They've been with us for most of their life.

It also provides high-quality, outstanding care for patients. They get their medications, imaging, and specialist visits, and they have a great patient experience. It's great for skill sustainment when health care professionals are seeing more complex patients, continuing to hone their skills and keep them sharp.

Question: How do you see strengthening the partnership the MHS has with the Department of Veterans Affairs?

Ferrara: The VA can have more demand than they can supply, and we often have more supply; we have excess supply. It’s a great opportunity to meet both of our missions across the country. Veterans may have more complex medical issues than our young, active duty personnel who are often healthy. It provides a robust clinical mix for us and is culturally aligned. Veterans enjoy receiving care at our MTFs. It provides another source of revenue, and it's good for the taxpayer. It’s a great opportunity and unique in government, where we can have wins across the board.

One example of how this has been successful is in El Paso (William Beaumont Army Medical Center). The VA and the hospital have partnered, referring 12,000 surgical patients a year to us. This can generate high value for our combat readiness mission in neurosurgery, orthopedics, and general surgery.

Question: What message would you like to share with the MHS force?

Ferrara: I’d like to thank them for the work they do. During my site visits, one thing that inspires me is the common refrain: “We just find a way to get the job done.” I know that folks have innovation and ingenuity — but most of all, it's driven by a focus on mission, on taking caring of patients, and on being ready to defend the country. I am fighting hard on their behalf every day. I'll continue to do that. That's what I consider my top priority and my primary mission.

Surveillance snapshot: Chikungunya in Military Health System beneficiaries, 2020–2024

Thu, 01 Jan 2026 00:00:00 Z

Chikungunya is a mosquito-borne viral disease that can cause severe joint pain, fever, and other short- or long-term symptoms.¹ Chikungunya is endemic to tropical and subtropical regions, with cases and outbreaks recorded in more than 100 countries.² The U.S. Food and Drug Administration (FDA) recently approved 2 chikungunya vaccines: a live-attenuated vaccine called IXCHIQ in November 2023, and a virus-like particle vaccine called VIMKUNYA in February 2025.³ These vaccines are recommended for those traveling to high-risk areas. The FDA recently suspended the U.S. license for IXCHIQ in August 2025, however, citing vaccine safety concerns.⁴

This analysis was conducted to answer questions from military health leadership about the risk of chikungunya infection to service members and their families. The analysis employed data published in prior MSMR articles^5-7 to provide case counts for all Military Health System (MHS) beneficiaries from 2020 through 2024. Data were drawn from the Defense Health Agency’s Disease Reporting System internet (DRSi), and were confirmed via medical chart review.

Ten cases of chikungunya virus disease among MHS beneficiaries were documented from 2020 through 2024 (Table). Five cases were recorded in service members, 3 among family members (all spouses), and 2 in other beneficiary types (i.e., not service members or dependents). One case was acquired while on deployment to multiple locations in Southeast Asia; no other cases were related to official travel or deployment. Most cases were related to unofficial travel.

Polyarthralgia, or pain in multiple joints, was the most documented symptom (n=7). Other commonly reported symptoms included fever, rash, and myalgia. Two cases had long-term symptoms (i.e., lasting longer than 12 weeks), and 2 cases were hospitalized. No cases had evidence of prior chikungunya vaccination in their medical records.

The small number of cases, hospitalizations, and evidence of long-term symptoms reported in the past 5 years suggest that risk of chikungunya virus disease to MHS beneficiaries is small. Use of standard preventive measures including personal protective equipment and vaccination should, however, continue to be encouraged when indicated for service members and other beneficiaries traveling to high-risk areas.

References

U.S. Centers for Disease Control and Prevention. Chikungunya Virus. U.S. Dept. of Health and Human Services. Accessed Oct. 3, 2025. https://www.cdc.gov/chikungunya/index.html
U.S. Centers for Disease Control and Prevention. Areas at Risk for Chikungunya. U.S. Dept. of Health and Human Services. Accessed Oct. 3, 2025. https://www.cdc.gov/chikungunya/data-maps/index.html
U.S. Centers for Disease Control and Prevention. Chikungunya Vaccine Information for Healthcare Providers. U.S. Dept. of Health and Human Services. Accessed Oct. 3, 2025. https://www.cdc.gov/chikungunya/hcp/vaccines/index.html
U.S. Food and Drug Administration. FDA Update on the Safety of Ixchiq (Chikungunya Vaccine, Live), August 2022, 2025. U.S. Dept. of Health and Human Services. Accessed Oct. 3, 2025. https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/fda-update-safety-ixchiq-chikungunya-vaccine-live
O’Donnell FL, Fan M, Stahlman S. Surveillance for vector-borne diseases among active and reserve component service members, U.S. Armed Forces, 2016-2020. MSMR. 2021;28(2):11-15. Accessed Nov. 18, 2025. https://www.health.mil/reference-center/reports/2021/02/01/medical-surveillance-monthly-report-volume-28-number-02
O’Donnell FL, Stahlman S, Fan M. Surveillance for vector-borne diseases among active and reserve component service members, U.S. Armed Forces, 2010–2016. MSMR. 2018;25(2):8-15. Accessed Nov. 18, 2025. https://www.health.mil/reference-center/reports/2018/01/01/medical-surveillance-monthly-report-volume-25-number-2
Stahlman SL, Langton RS. Surveillance snapshot: chikungunya in service members of the U.S. Armed Forces, 2016–2022. MSMR. 2023;30(12):11. Accessed Nov. 18, 2025. https://www.health.mil/news/articles/2023/12/01/msmr-chikungunya

Authors’ Affiliation

Defense Health Agency, Public Health Directorate, Armed Forces Health Surveillance Division, Epidemiology and Analysis Branch, Silver Spring, MD: Dr. Stahlman; Defense Health Agency, Defense Centers for Public Health–Aberdeen, MD: Ms. Scatliffe-Carrion, Dr. McCannon

Letter from the Editor in Chief

Thu, 01 Jan 2026 00:00:00 Z

Thank you for being one of the many MSMR readers in 2025. MSMR’s mission is to publish operationally relevant, timely, and descriptive epidemiological articles that provide accurate data on topics vital to the health, safety, and resilience of the U.S. Armed Forces. As a product of the Armed Forces Health Surveillance Division (AFHSD), within the Public Health Directorate (PHD) of the Defense Health Agency (DHA), MSMR is a peer-reviewed journal published each month on health.mil that is also indexed on PubMed and archived on PubMed Central (PMC).

The MSMR role, supporting the combined missions of AFHSD, PHD, and DHA, remains vital. The need for appropriate database utilization, information synthesis, and methodologically valid analysis remains the ‘gold standard’ of epidemiological surveillance and medical knowledge development. MSMR continuously strives for timeliness with careful deliberation, relevance with objectivity, and scientific validity focused on force readiness, force health protection, and force resilience.

Although we publish MSMR for both warfighter readiness as well as military and civilian public health surveillance, planning, and response—with many individuals and organizations both within and outside DHA to thank—it is our readers such as you who are in our thoughts when we assemble, edit, and publish each issue. 2025 has truly been a high water mark for MSMR due to increased content, particularly in special topical issues, and significantly enhanced readership metrics.

MSMR published three special issues in 2025, which enhanced MSMR focus on unique military readiness and force health protection concerns. Our 30th anniversary issue in April featured 10 articles covering many operationally important topics including, but not limited to, historical highlights, influenza modeling, global pathogen surveillance, HIV testing, in addition to the annual malaria case update. In May, MSMR published a military women’s health and readiness issue, which also included 10 reports, covering a breadth of topics from infertility and contraception trends to military women’s health and readiness research and female warfighter performance in extreme environments.

MSMR’s third special issue, in September, presented our annual review of illnesses and injuries within the active, reserve, and Guard components of the U.S. Armed Forces in addition to its Military Health System (MHS) beneficiaries. The issue examined numbers and trends in hospitalization and ambulatory visits, deployment morbidity burdens, selected medical evacuations and telehealth usage by the active component members. Publishing morbidity burdens for the entire MHS in one issue provides our readers with a valuable reference document of recent case numbers and trends.

Rigorous data collection, exacting analysis, manuscript writing and review, and painstaking submission for publication is hard work, and we appreciate and heartily thank each author in 2025 for their scholarship and dedication. The MSMR editorial staff deeply appreciates the quality and operational value of every submission. Our manuscript submissions in 2025 increased by nearly two-thirds, and those increased submissions resulted in greater MSMR content, providing our readers with even more accurate, timely, and clear epidemiological reporting.

We also heartily thank our subject matter expert reviewers. Our external reviewers provide robust assessments and insightful comments informed by their professional knowledge and years of expertise that assist our authors’ refinement of their manuscripts. For each original manuscript submitted, our double-blind peer review process involves two independent subject matter experts who contribute clinical and professional perspectives, enhanced analyses, and additional editorial rigor that improves the quality of MSMR reporting.

MSMR began archiving on PMC in January 2024, enabling free, open, permanent access to our peer-reviewed content. Over the past two years, readership of MSMR content on PMC has steadily grown, expanding our impact within the international scientific community. The MSMR online ‘hit’ rate on PMC was 50% higher in 2025 compared to 2024.

Our reach and readership continue to increase as the appetite for high quality, evidence-based, military health-specific information continues to grow. The Department of War public health community is focused on collecting, publishing, and applying the increasing knowledge base to positively influence health awareness and outcomes. MSMR’s advances in 2025 are the result of hard work by the MSMR staff in concert with the excellent manuscripts submitted by public health investigators and researchers, not only from the various DHA organizations, but civilian and international contributors as well. MSMR staff works in collaboration with DHA PHD staff to more broadly share the findings that result from the substantial medical data available within DHA and the MHS.

Each MSMR issue comes together over the course of months, beginning with manuscript submission by our authors, comprehensive internal review by our editors, external review by external subject matter experts, painstaking responses and revisions by the authors, meticulous copy editing, and publishing on health.mil, indexing on PubMed, and archiving on PMC. We could not accomplish our mission to publish this operationally relevant journal without our authors, reviewers and, of course, our readers. Many thanks to you all!

Our plans for 2026 are robust. We will continue to increase our published content, and aim to publish earlier within the month, to increase the timeliness of our reporting. To return to my first Letter form the Editor’s Desk, published in January 2024, our mission and dedication remain firm and unchanged. I wrote then and reiterate, “In the most recent Armed Forces Health Surveillance Division (AFHSD) Annual Report, MSMR is referred to as the “premiere medical peer-reviewed journal published by the AFHSD and Defense Health Agency (DHA),” which provides “evidence-based estimates of the incidence, distribution, impact and trends of illness and injury among U.S. military service members and associated populations.” MSMR has a distinguished legacy of excellence and professional rigor. As we begin our 31st year, the MSMR staff is honored to pick up and carry that standard further. MSMR continues to be vigilant and undaunted by the continued high stakes role of public health but successes of 2025 position us well to continue to serve “those who serve” in 2026.

Very Respectfully,
Robert Johnson, MD, MPH, MBA
Col (ret) USAF
Editor-in-Chief
Medical Surveillance Monthly Report

Guillain-Barré Syndrome clinical characteristics and outcomes among U.S. active component service members, 2014–2022

Thu, 01 Jan 2026 00:00:00 Z

Abstract

An examination of Guillain-Barré Syndrome (GBS) cases among U.S. active component service members from 2014 through 2022 revealed an incidence rate of 1.6 cases per 100,000 person-years. Individuals younger than age 20 years and those in basic training exhibited higher incidence. The type of antecedent event, either illness or immunization, was not associated with higher disability ratings at long-term follow-up. The analysis also quantified morbidity among service members with GBS, finding that 28.0% of cases had a subsequent chronic pain diagnosis, and 28.7% of cases were referred to the medical evaluation board. The need for neuropathic pain medication during the acute phase predicted poorer long-term functional outcomes. Furthermore, electrodiagnostic evidence of axonal or mixed nerve damage correlated with greater disability after 1 year. Although basic trainees had higher incidence, their long-term morbidity was comparable to other groups. These findings underscore the considerable impact that GBS can have on affected military personnel and identify factors associated with long-term complications.

What are the new findings?

There were 1.6 cases of Guillain-Barré syndrome per 100,000 person years among active component U.S. service members from 2014 through 2022. There was no association between persistent disability and associated antecedent event (e.g., infection or immunization). Many patients experienced incomplete recovery, with 28.7% resulting in medical board referrals. Persistent disability was independently associated with chronic pain diagnosis.

What is the impact on readiness and force health protection?

Despite the low incidence rate of the disorder, approximately 29% of U.S. service member GBS cases experienced incomplete recovery that required medical board referral. Service members appear to be at a higher risk for GBS during initial recruit basic training, potentially due to increased exposure to infections and immunization requirements at accession.

Background

Guillain-Barré syndrome (GBS) is an acute immune-mediated polyradiculoneuropathy. GBS stems from an autoimmune response related to an antecedent illness, immunization, or other immune reaction causing damage to myelin (acute inflammatory demyelinating polyneuropathy, or AIDP) or axons (acute motor axonal neuropathy, or AMAN) of the peripheral nerves and ganglia. AIDP is the predominant variant seen in North America.¹

GBS occurs with an overall worldwide incidence rate (IR) of 0.6–4.0 cases per 100,000 people per year with higher rates reported in North America, 2.2–4.2 cases per 100,000.^2-8 One study from 2009 found a slightly higher incidence of GBS in the active duty U.S. military population compared to the general population.⁵ It is more common in men and can affect all age groups.¹

Mortality due to GBS varies in reported studies, from 2% to 10%, with predictors including advanced age, mechanical ventilation, and cardiopulmonary complications.^1-4,6 Morbidity with severe disability can be seen in upwards of 20% of patients, with predictors including advanced age, mechanical ventilation, preceding diarrheal illness, and high-grade disability in the acute phase.^1-4 Pain is a common symptom upon presentation and can persist long term, significantly affecting quality of life.⁹

Classic clinical presentation of GBS manifests as a progressive ascending muscle weakness with decreased or absent deep tendon reflexes.⁶ Patients also present with sensory symptoms, ataxia, lower back pain, and cranial nerve involvement that range in severity.⁶ Autonomic dysfunction is also common and can be fatal.⁶ Variants include pure motor, pure sensory, Miller Fisher, pharyngeal-brachial, and paraparetic.⁶

There are no specific biomarkers associated with GBS. Diagnosis of GBS is typically based on a thorough history and clinical examination. Certain diagnostic tools may support diagnosis, including cerebrospinal fluid (CSF) analysis, serum antibody testing, magnetic resonance imaging (MRI), and electrodiagnostic studies.

The disease timeline is typically monophasic, with progression over 2 weeks and symptom nadir (i.e., most critically ill point) around 4 weeks after onset.⁶ Severity is variable, and up to one-fourth of cases require mechanical ventiliation.^6,8 Close monitoring and early initiation of intravenous immunoglobulins (IVIG) or plasma exchange (PLEX) is essential for accelerating recovery.⁷ Uncommonly, acute clinical presentation of GBS can herald another neurological disorder, such as chronic inflammatory demyelinating polyneuropathy (CIDP) or neurological presentation of other systemic diseases such as lupus or infection.

Antecedent respiratory or gastrointestinal illness can be identified in up to three-fourths of patients presenting with GBS.^1,8,10 Campylobacter jejuni is the most common prior infection, with 30% of cases in 1 study demonstrating serological evidence of the infection.¹⁰ Other infectious etiologies include Mycoplasma pneumonia, cytomegalovirus, Epstein-Barr virus, hepatitis E virus, Zika, dengue, and influenza.^1,8,10 Asymptomatic infections have also been detected by serological testing, which may suggest higher rates of antecedent illness.¹⁰

The risk of immunization-related GBS was originally based on the 1976 swine influenza vaccine, but studies investigating influenza immunization after 1976 had mixed results, with most showing no causal relationship.¹¹ Low, but increased risk of GBS following adenovirus-vectored COVID-19 vaccines was lower than the risk identified with the 1976 influenza vaccine.¹² The same study also found reduced risk of GBS with the messenger RNA (mRNA) COVID-19 vaccines.¹² The U.S. Centers for Disease Control and Prevention (CDC)’s Advisory Committee on Immunization Practices (ACIP) states that GBS is not a precaution for future immunizations, unless it occurred within 6 weeks of receiving a tetanus-toxoid-containing vaccine or an influenza vaccine.¹³

Immunizations are administered upon accession into military service, unless a service member provides prior documentation of prior immunization or serological testing showing presence of antibodies.¹⁴ Immunization administration upon military accession is recommended before or at the beginning of basic training, to help mitigate risk of contagious disease in close quarters environments.¹⁴ Additional immunizations such as yellow fever, Japanese encephalitis, and rabies may be required depending upon travel or area of operation requirements.¹⁴ COVID-19 immunization was mandated for all military members in August 2021; however, the mandate was rescinded in January 2023. Immunizations identified by the CDC of potential concern are influenza and tetanus vaccines, however, other vaccines have also been implicated, including yellow fever and rabies.^15,16

A previous military population study, of matched case-control design, evaluated the association between GBS and acute gastrointestinal infections and deployment from 1999 through 2007.⁵ That 2009 study identified a slightly higher incidence in the military cohort compared to the general population, but it was limited by retrospective database review without medical record review.⁵

The objective of the current study was to describe the incidence, clinical characteristics (including antecedent illness or immunization), clinical course, and electrodiagnostic findings of U.S. active component service members (ACSMs) with clinically confirmed GBS from 2014 through 2022. Due to the timeline chosen for data extraction, it includes 2 years of COVID-19 immunization in addition to yearly influenza immunization. An updated, comprehensive understanding of the clinical characteristics of GBS, its disease course, and their readiness implications will supply health care providers with knowledge that can aid patient education, improve prognostication discussions, and potentially assuage apprehensions about immunizations in relation to GBS risk.

Methods

Potential cases of GBS were identified as those with documentation of an International Classification of Diseases, 9th or 10th Revision, Clinical Modification (ICD-9-CM/ICD-10-CM) code (357.0 or G61.0, respectively) in an inpatient or outpatient medical encounter from January 1, 2014 through December 31, 2022 among ACSMs in the U.S. Army, Navy, Marine Corps, Coast Guard, Air Force, or Space Force. The data came from medical records maintained in the Defense Medical Surveillance System (DMSS) that the authors obtained from the Armed Forces Health Surveillance Division (AFHSD) in 2023. DMSS ICD-9-CM/ICD-10-CM code queries included diagnostic positions of 4 digits for outpatient records and 9 digits for inpatient records. The records examined included those from military hospitals and clinics as well as civilian medical facilities if reimbursement was sought through the Military Health System (MHS). The 2014 start date was chosen to capture treatment and prescription data through DMSS. The Walter Reed National Military Medical Center determined this project to be human subject research exempt from institutional board review.

A list of 401 potential cases identified in DMSS was sent to the primary investigator’s research team of neurologists and neurology residents for individual record review (Figure). Cases were excluded during individual chart review when the diagnosis code was entered with no other supporting information to confirm diagnosis, or the diagnosis was revised during the acute treatment period. Cases were also excluded if the diagnosis code referenced childhood or prior history of GBS before January 2014.

Following individual chart reviews, 191 cases were identified as acute presentations of GBS. Cases were validated based on a culmination of consistent clinical history, symptoms upon patient presentation, physical examination findings, and treatment choice consistent with GBS diagnosis. Supporting diagnostic evidence including CSF studies, serum antibody testing, lumbar spine MRI findings, and electrodiagnostic testing were also reviewed to aid case validation. Data collected for the 191 identified cases included patient demographics, clinical information, electrodiagnostic testing data, and related case outcomes.

The acute phase of GBS was considered as the time from initial clinical evaluation to either end of acute treatment course, final hospitalization, or acute rehabilitation discharge. Clinical information collected in the acute phase included presence of antecedent illness or prior immunization, timeline of symptom onset, diagnostics (e.g., laboratory, imaging, electrodiagnostic data), primary treatments, pain treatment, hospital care and complications, and disability rating, using the Modified Rankin Scale (MRS), at the most critically ill point (i.e., nadir) of acute presentation. Antecedent illness information was obtained from clinical history and review of clinical notes 30 days prior to presentation, for indications of acute illness appointments or infection treatments. Immunization information was obtained from clinical histories, reviews of medical chart immunization records, and reviews of clinical notes indicating immunization appointments within 30 days preceding patient presentation. Any immunization within 30 days was recorded according to type of immunization and date administered.

Clinical information collected after the acute phase included additional electrodiagnostic study data, time to recovery, chronic pain diagnosis, and long-term follow-up MRS. Electrodiagnostic testing results were classified as normal, demyelinating, or mixed/axonal. Demyelinating cases had isolated demyelinating features that could include prolonged or absent F-waves, prolonged distal latencies, or slowed conduction velocities. Axonal or mixed cases had either axonal features alone or axonal and demyelinating features. Axonal features could include low amplitude action potentials or spontaneous activity on electromyography.

Time to recovery was assessed by patient report of recovery, date returned to full duty, and medical evaluation board (MEB) referrals. MEB information was compared and validated with MEB information provided by the DMSS. Chronic pain diagnosis based on presence of ICD-9-CM or ICD-10-CM code (338.2 or G89) or documentation of chronic pain within the clinical note and was dichotomized as present or not.

During chart reviews, chronic pain diagnosis was included if it could be related to GBS diagnosis in documentation of chronic pain present since acute phase. A diagnosis of chronic pain was included if pain was a new symptom at time of GBS diagnosis and continued at 1 year follow-up or beyond. Cases were not included in the chronic pain category if chronic pain diagnosis was clearly attributable to another injury. Chronic pain diagnosis was independently confirmed by the primary investigator.

MRS determination was based on reviews of neurologists’ interpretations of clinical disability reports from histories and documented physical examination findings. If multiple clinical encounters were available after 1 year of follow-up, then the encounter closest to 1 year after the original diagnosis was used to determine MRS. The MRS scale is a disability scale graded from 0 to 6, with 0 indicating no symptoms present, 1 indicating minimal symptoms but ability to complete all usual activities, 2 indicating slight disability but able to perform daily activities without assistance, 3 indicating moderate disability requiring help and unable to walk alone without assistance,4 indicating moderate severe disability requiring assistance for own bodily needs, 5 indicating severe disability unable to attend own body needs without constant assistance, and 6 indicating death.¹⁷

All reviewers were trained on proper application of the MRS scale, and a small sampling of cases was provided to the reviewers prior to initiation of review to aid with inter-rater reliability. The primary investigator confirmed complementary assessments with all reviewers of the sample cases provided. A data collection sheet for the acute phase collected medical research council sum score, ventilation requirements, and medical complications during hospitalization, which aided determination of nadir MRS scores. The primary investigator independently confirmed all MRS scores with the data collection sheet and independent review.

The list of confirmed cases was returned to AFHSD for IR calculation. AFHSD used longitudinal personnel data in the DMSS to calculate the rate of clinically confirmed GBS per 100,000 person-years (p-yrs) of active component service. Person-time was censored at the incident diagnosis date. Person time for recruit basic training was identified using a standard AFHSD algorithm based on time in service, assigned military installation, branch of service, and other factors.

Case characteristics were described and compared by MRS and chronic pain diagnosis as outcomes after 1 year follow-up using Wilcoxon 2-sample tests and Chi-square or Fisher’s exact tests. To evaluate potential independent associations of case characteristics with each outcome, multivariable logistic regression models estimated adjusted odds ratios associated with several characteristics selected by the research team based both on their potential clinical relevance and association with the outcome in unadjusted analyses. Further adjustment was avoided to guard against model overfitting and to conform to the traditional minimum number of events per predictor (>10) in logistic regression. Low variance inflation factors in each model indicated that multi-collinearity was not a concern.

The dependent variables were MRS outcome and chronic pain diagnosis at 1 year or greater follow-up. MRS was defined as either 0 (asymptomatic) or greater than 0 (minimally symptomatic to severe disability). Independent variables included use of neuropathic pain treatment in the acute treatment phase, presence of pain in the acute phase, and significant disability (MRS>3) during the acute phase. A dichotomized MRS definition of greater than or equal to 3 was based both on observed elevated frequencies of each outcome in this stratum relative to lower MRS scores and by the small cell sizes in several MRS strata, which prevented further evaluation of MRS as an ordinal score in multivariable models. These analyses were performed using R (version 4.0.5).¹⁸

Results

The DMSS database identified 401 potential GBS cases by ICD-9-CM/ICD-10-CM codes alone (Figure). After individual chart reviews, 191 cases were identified as acute GBS. An IR of 1.6 confirmed GBS cases per 100,000 p-yrs was calculated for ACSMs from 2014 through 2022 (Table 1). Male service members had a slightly higher rate than female service members (1.7 and 1.0 cases per 100,000 p-yrs, respectively). There was a higher IR in those younger than age 20 years, at 3.6 cases per 100,000 p-yrs, and those in basic training recruit status (11.5 cases per 100,000 p-yrs).

An isolated antecedent illness within 30 days of diagnosis was noted in 94 of 191 (49.2%) cases (Table 2). Median time from illness start to diagnosis date was 11 days. Isolated immunization within 30 days of the date of diagnosis was seen in 28 (14.7%) cases. Median time from immunization to date of diagnosis was 15 days. Approximately one-fourth of cases, 46 of 191 (24.1%), had both an antecedent illness and immunization within 30 days of the preceding syndrome presentation.

The most reported symptoms were upper respiratory illness or influenza-like illness, which were seen in 101 (52.8%) cases. COVID infection was only noted in 4 (2.1%) cases. Influenza was the most common immunization received within the preceding 30 days (11.5%). COVID immunization had been received in 9 (4.7%) cases. Among the 28 basic training recruits, 9 of the 28 (32.1%) had a prior illness only, 7 of the 28 (25%) had a previous immunization only, and 12 of the 28 (42.8%) had both a concurrent preceding illness and immunization (data not shown).

Pain was reported during initial patient presentation in 141 of 191 (73.8%) cases (Table 2). Over three-fourths of cases demonstrated no significant disability to moderate disability at the most critical point of initial presentation, ranging from MRS 1 in 40 cases (20.9%), MRS 2 in 71 cases (37.2%), and MRS 3 in 33 cases (17.3%). Almost one-fourth of cases had moderate to severe disability at nadir, with MRS 4 (n=29, 15.2%) or 5 (n=16, 8.4%).

All but 14 patients were hospitalized for monitoring and management (Table 2). The median duration of hospitalization was 7 days (range 2–54 days). Eleven patients received no documented treatment. Most patients received IVIG as primary treatment (n=155, 81.2%). Eleven patients received IVIG in combination with PLEX. Seven patients received PLEX alone, and 7 received steroids alone for primary treatment. Neuropathic pain medication was given to 48.2% (n=92) of patients.

Over half of cases (n=108, 56.5%) received electrodiagnostic testing. Among the 108 cases with electrodiagnostic testing, results were interpreted as normal in 27 cases; evidence of isolated demyelinating features was noted in 53 cases; and 28 cases had axonal or mixed findings (Table 2). Serial electrodiagnostic studies were completed in 45 of 108 (41.6%) cases (data not shown). Follow-up studies were normal in 15 of 45 (33.3%) cases, with median follow-up testing at 51 days (range 7–896 days). Demyelinating features were present in 20 of 45 cases (44.4%), with median follow-up testing at 152 days (range 6–1,063 days). Axonal or mixed features were observed in 10 of 45 cases (22.2%) with median follow-up testing at 122 days (range 19–1,191 days). Five cases had more than 2 serial electrodiagnostic tests completed (4 of 5 were axonal, range 35–1,088 days). One case with primary axonal damage had persistent fibrillation potentials and positive waves more than 1 year after original diagnosis (data not shown).

Following the initial treatment course, 36 patients had recurrent or persistent symptoms without interval improvement after initial hospitalization (data not shown). One case (0.5%) was believed to be recurrence of GBS, 3.5 years after the initial episode. Five cases experienced symptom recrudescence within 90 days, attributed to the initial disease presentation, that were subsequently treated with second rounds of IVIG. Five cases had recurrent symptoms more than 90 days later, without other objective evidence of recurrence, with 1 receiving IVIG treatment again 6 years later.

Long-term follow-up more than 1 year after initial diagnosis was available for 177 cases. Five cases had no clear improvement after acute presentation and continued to report persistent symptoms at long-term follow-up. Following the acute phase, alternative diagnoses (i.e., other than GBS) were made or suspected in 34 cases. Among those 34 cases, CIDP was the ultimate diagnosis in 13 cases; multifocal motor neuropathy was diagnosed in 2 cases; and other neurological disorders were suspected in 19 cases, including 10 cases of functional neurological disorder. Median time to symptom recurrence for CIDP was 33 days, and 130 days for all others with polyphasic presentations.

After excluding the 34 cases with possible alternative long-term diagnoses, there were 143 cases of GBS with more than 1 year of follow-up (Table 3). MRS was extracted from clinical encounters at least 1 year after original diagnosis. During follow-up after 1 year, 73 of 143 (51.0%) cases had returned to baseline, with MRS 0. The outcomes of long-term follow-up for all other cases were distributed from MRS 1 in 46 (32.2%) cases, MRS 2 in 17 (11.9%) cases, MRS 3 in 3 (2.1%) cases, MRS 4 in 3 (2.1%) cases, and MRS 6 in 1 case with death unrelated to GBS.

The average time for return to duty in those with full recovery was 5 months (median 4 months, range 0.5–40 months). Type of antecedent clinical event and recruit status were not associated with higher MRS at 1 year follow-up (p=0.182 and p=0.077, respectively) (Table 4a). Patients with axonal or mixed electrodiagnostic results were more likely to have MRS greater than 0 at 1 year versus patients with demyelinating or normal electrodiagnostic testing (p<0.001) (Table 4a).

Chronic pain associated with GBS diagnosis was seen in 40 (28.0%) of the 143 cases with no other alternative diagnosis at long-term follow-up (Table 3). Chronic pain diagnoses were seen more commonly in patients with MRS greater than 0 at 1 year (p<0.001) (Table 4a). Among the 143 cases at long-term follow-up, MEB was initiated for 41 (28.7%) cases, and 93 cases (65.0%) returned to duty. Twenty-six of the 41 referred for MEB had a chronic pain diagnosis (data not shown).

Of the 40 patients with chronic pain diagnoses, 33 (82.5%) initially required neuropathic pain treatment (p<0.001) (Table 4b). In a multi-variable logistic regression model of relevant clinical characteristics as predictors of MRS outcome and chronic pain diagnosis at long-term follow-up, neuropathic pain treatment was associated with greater risk of MRS greater than 0 (OR 6.8; 95% CI 2.8, 17.7; p<0.001) and resultant chronic pain diagnosis (OR 7.9; 95% CI 2.7, 28.0; p<0.001) independent of reported pain and MRS at nadir (Table 5).

Discussion

This study provides an update on clinical characteristics and outcomes in GBS among a large military cohort. GBS shares an overall similar IR in the U.S. military population when compared to reported rates globally^1,4,7-9 but has a lower incidence when compared to directly to other North American and European cohorts (1.9 to 4.2 per 100,000 p-yrs).^2,7 GBS severity is variable, but there were no fatalities attributable to GBS in this cohort. This lack of mortality may be related to a lower rate of mechanical ventilation (10.4% vs. up to 23% in other studies^3,8) and an overall healthier and younger active duty military population.

Results of electrodiagnostic testing can be helpful in predicting long-term MRS outcomes, but only slightly more than half of cases in this study had electrodiagnostic testing available for review. This study did not identify a clear role for serial electrodiagnostic testing. Serial testing can be beneficial, however, if the diagnosis is in question or the patient has persistent or recurring symptoms. It is notable that 1 axonal case had persistent fibrillation potentials and positive waves in serial electrodiagnostic testing more than 1 year after initial diagnosis; this appears to have captured the natural course of the disease rather than representing a second pathology.

This study quantified morbidity associated with GBS in U.S. ACSMs, as seen in the 28.0% of cases associated with a subsequent chronic pain diagnosis, and in 28.7% of cases referred to the MEB. The 2009 military study reported 20% of service members with continued medical visits related to GBS 1 year post-diagnosis, and other studies report approximately 20% with long-term disability.^4,5 There were similar rates of reported pain in the acute period (~70%) and long-term follow-up period (~25%) compared to a recent civilian cohort.⁹ The need for treatment with neuropathic pain medication could be an early indicator for morbidity, as it was independently associated with MRS of greater than 0 at follow-up. This may represent an additional and relatively early clinical feature to consider when determining overall prognosis. Additionally, it may provide an impetus to consider earlier or more aggressive treatment in certain cases. Future prospective studies could provide further clarification.

Determination of the type of GBS, axonal versus demyelinating, can be helpful with understanding associated acute and chronic pain, prognostication, and differentiating GBS from other mimickers.^4,6,9 A recent study highlighted that acute pain may be more pronounced in axonal variants while chronic pain may be associated with demyelinating, however, this was in a cohort of Asian subjects, who typically have higher axonal rates.⁹ If there is diagnostic or prognostic uncertainty after the acute phase, electrodiagnostic testing should be pursued.

There was no significant association between type of preceding event (e.g., infection or immunization) and long-term morbidity. Those in basic training recruit status did, however, have a higher incidence when compared to other groups. The recruit population typically receives multiple immunizations upon arrival, and they are also housed in close quarters, increasing potential infection transmissibility. This was reflected in this analysis, as most recruits had a preceding illness or immunization within 30 days of symptom onset. This study was not designed to determine direct causal relationships with immunization.

The main limitation of this study is its retrospective design. While these findings can provide insights, correlation cannot be established. Utilization of medical encounter data is both limited by accuracy of documentation and subject to reporting bias. Cases may be under-reported due to reliance on appropriate ICD-9-CM/ICD-10-CM code placement. Risk factors cannot be assessed with this study design. Antecedent illness and prior immunization data can be incomplete if not documented in clinical notes, or if service members received immunizations out of network without records in MHS medical charts. Evaluating morbidity by using an MRS greater than 0 may over-estimate significant disability.

This study provides an important update on GBS in the active component population of the U.S. military for MHS clinicians and may help guide future research. Given the increased incidence during the recruit training period in this study, it is prudent for health care providers working with populations such as military recruits to consider referral to an appropriate level of care if suspicion of GBS arises, in addition to ensuring appropriate immunization counseling and addressing elements to help mitigate close quarters disease transmissibility. Despite the increased incidence of GBS in recruits, no evidence supported a higher risk of long-term morbidity in the U.S. active component population.

References

van den Berg B, Walgaard C, Drenthen J, et al. Guillain-Barré syndrome: pathogenesis, diagnosis, treatment and prognosis. Nat Rev Neurol. 2014;10(8):469-482. doi:10.1038/nrneurol.2014.121
Bragazzi NL, Kolahi AA, Nejadghaderi SA, et al. Global, regional, and national burden of Guillain–Barré syndrome and its underlying causes from 1990 to 2019. J Neuroinflammation. 2021;18(1):264. doi:10.1186/s12974-021-02319-4
Alshekhlee A, Hussain Z, Sultan B, Katirji B. Guillain-Barré syndrome: incidence and mortality rates in US hospitals. Neurology. 2008;70(18):1608-1613. doi:10.1212/01.wnl.0000310983.38724.d4
Chiò A, Cocito D, Leone M, et al. Guillain-Barré syndrome: a prospective, population-based incidence and outcome survey. Neurology. 2003;60(7):1146-1150. doi:10.1212/01.wnl.0000055091.96905.d0
Nelson L, Gormley R, Riddle MS, Tribble DR, Porter CK. The epidemiology of Guillain-Barré syndrome in U.S. military personnel: a case-control study. BMC Res Notes. 2009;26(2):171. doi:10.1186/1756-0500-2-171
Willison HJ, Jacobs BC, van Doorn PA. Guillain-Barré syndrome. Lancet. 2016;388(10045):717-727. doi:10.1016/s0140-6736(16)00339-1
Shahrizaila N, Lehmann HC, Kuwabara S. Guillain-Barré syndrome. Lancet. 2021;397(10280):1214-1228. doi:10.1016/s0140-6736(21)00517-1
Finsterer J. Triggers of Guillain-Barré syndrome: Campylobacter jejuni predominates. Int J Mol Sci. 2022;23(22):14222. doi:10.3390/ijms232214222
Papri N, Mohammed A, Rahman MM, et al. Pain determinants and quality of life in Guillain-Barré syndrome: a prospective cohort study. BMJ Neurol Open. 2024;6(2):e000925. doi:10.1136/bmjno-2024-000925
Leonhard SE, et al, IGOS Consortium. An international perspective on preceding infections in Guillain-Barré syndrome: the IGOS-1000 cohort. Neurology. 2022;99(12):e1299-e1313. doi:10.1212/wnl.0000000000200885
Salmon DA, Proschan M, Forshee R, et al. Association between Guillain-Barré syndrome and influenza A (H1N1) 2009 monovalent inactivated vaccines in the USA: a meta-analysis. Lancet. 2013;381(9876):1461-1468. doi:10.1016/s0140-6736(12)62189-8
Censi S, Bisaccia G, Gallina S, Tomassini V, Uncini A. Guillain-Barré syndrome and COVID-19 vaccination: a systematic review and meta-analysis. J Neurology. 2024;271(3):1063-1071. doi:10.1007/s00415-024-12186-7
Eiffert SR, Stürmer T, Thorpe CT, et al. Vaccine patterns among patients diagnosed with Guillain-Barré syndrome and matched counterparts in a Medicare supplemental population, 2000–2020. Vaccine. 2023;41(39):5763-5768. doi:10.1016/j.vaccine.2023.08.014
Headquarters, Departments of the Army, the Navy, the Air Force, and the Coast Guard. Army Regulation 40-562, BUMEDINST 6230.15B, AFI 48-110_IP, CG COMDTINST M6230.4G–Medical Services: Immunizations and Chemoprophylaxis for the Prevention of Infectious Diseases. U.S. Dept. of Defense. Oct. 7, 2013. Accessed Nov. 19, 2025. https://www.med.navy.mil/portals/62/documents/nmfa/nmcphc/root/field%20activities/pages/nepmu6/operational%20support/environmental%20health/bumedinst-6230-15b-immunizations-and-chemoprophylaxis.pdf
Staples J, Gershman M, Fischer M, U.S. Centers for Disease Control and Prevention. Yellow fever vaccine: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2010;59(rr-7):1-27. Accessed Nov. 19, 2025. https://www.cdc.gov/mmwr/pdf/rr/rr5907.pdf
Hemachudha T, Griffin D, Chen W, Johnson R. Immunologic studies of rabies vaccination-induced Guillain-Barré syndrome. Neurology. 1988;38(3):375-378. doi:10.1212/wnl.38.3.375
Saver JL, Chaisinanunkul N, Campbell BCV, et al, XIth Stroke Treatment Academic Industry Roundtable. Standardized nomenclature for Modified Rankin Scale global disability outcomes: consensus recommendations from Stroke Therapy Academic Industry Roundtable XI. Stroke. 2021;52(9):3054-3062. doi:10.1161/strokeaha.121.034480
The R Foundation. The R Project for Statistical Computing. Accessed Nov. 19, 2025. https://www.r-project.org

Author Affiliations

Naval Aerospace Medical Institute, Pensacola, FL: LCDR Elliott; Epidemiology and Analysis Branch, Armed Forces Health Surveillance Division, Public Health Directorate, Defense Health Agency, Silver Spring, MD: Dr. Stahlman; Walter Reed National Military Medical Center, Bethesda, MD: Dr. Watson, Dr. Sedarsky; Landstuhl Regional Medical Center, Landstuhl, Germany: MAJ Denkensohn

Disclaimer

The views expressed in this report are those of the authors and do not necessarily reflect the official policy or position of the Defense Health Agency, Department of War, nor the U.S. Government.

LCDR Elliott and MAJ Denkensohn are military service members; Dr. Stahlman and Dr. Watson are employees of the U.S. Government. This work was prepared as part of official duties. Title 17, U.S. Code Section 105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S. Code Section 101 defines a U.S. Government work as a work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties.

Acknowledgment

LT Mark Boyer

Reportable medical events at Military Health System facilities through week 40, ending October 4, 2025

Thu, 01 Jan 2026 00:00:00 Z

Total active component cases reported per week are displayed for the top 5 RMEs for the previous year. Each month, the graph is updated with the top 5 RMEs, and is presented with the current month’s (September 2025) top 5 RMEs, which may differ from previous months. COVID-19 is excluded from these graphs due to changes in reporting and case definition updates in 2023.

References

Armed Forces Health Surveillance Division. Armed Forces Reportable Medical Events. Accessed Feb. 28, 2024. https://health.mil/reference-center/publications/2022/11/01/armed-forces-reportable-medical-events-guidelines
Defense Manpower Data Center. Department of Defense Active Duty Military Personnel by Rank/Grade of Service. Accessed Feb. 28, 2024. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports
Defense Manpower Data Center. Armed Forces Strength Figures for January 31, 2023. Accessed Feb. 28, 2024. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports
Navy Medicine. Surveillance and Reporting Tools–DRSI: Disease Reporting System Internet. Accessed Feb. 28, 2024. https://www.med.navy.mil/navy-marine-corps-public-health-center/preventive-medicine/program-and-policy-support/disease-surveillance/drsi

Authors’ Affiliation

Defense Health Agency, Disease Epidemiology Branch, Defense Centers for Public Health–Aberdeen

Case report: An atypical Ross River Virus infection in an Australian Army service member

Thu, 01 Jan 2026 00:00:00 Z

Arboviral diseases, transmitted by arthropods such as mosquitoes, represent a significant and ongoing threat to the health, readiness, and mission capability of U.S. military personnel deployed in endemic regions.^1,2 Ross River virus (RRV), an alphavirus transmitted by mosquitoes, is endemic to Australia and causes an average of 5,000 cases annually.³ RRV is also endemic as well as epidemic in many South Pacific Islands including Papua New Guinea, Solomon Islands, Fiji, American Samoa, New Caledonia, and Cook Islands.⁴ These countries are frequent locations for U.S. military training and joint operations (Figure 1).

RRV is not a new threat to U.S. military operations. In 1997, an outbreak of RRV-related epidemic polyarthritis (EPA) occurred among 19 U.S. Navy personnel during a joint exercise at the Shoalwater Bay Training Area in Queensland.⁵ A pre- and post-deployment serum survey of 2,500 U.S. marines deployed to Australia on 6-month training rotations confirmed RRV seroconversion, indicating RRV local transmission during training deployments.⁶

U.S. military presence in the South Pacific has increased recently, with several multi-national, joint exercises in response to strategic pressures arising from the expansion of China’s southwestern Pacific military presence. More than 35,000 military personnel, including Australian and U.S. forces, and representatives from over 19 nations took part in Exercise Talisman Sabre 2025, the largest military exercise ever held in Australia and the first in Papua New Guinea.⁷

RRV is the most frequently reported arboviral disease in Australia, with approximately over 63,000 cases recorded in Queensland alone from 1993 to 2020.^8,9 The ecology of RRV is complex: Over 40 mosquito species have been identified as potential vectors, and more than 18 wild and domestic animal species are suspected as amplifying hosts or reservoirs.¹⁰ These factors contribute to unpredictable and seasonal RRV outbreaks. RRV is particularly prevalent in the Northern Territory and Queensland, where human cases are reported year-round.¹¹

Although some RRV infections are asymptomatic or sub-clinical (approximate symptomatic-to-asymptomatic ratio 1:3), symptomatic cases can develop into EPA, a debilitating condition characterized by joint inflammation. Additional symptoms, such as rash, low-grade fever, malaise, myalgia, lymphadenopathy, headache, depression, and fatigue, may accompany EPA.^12-14 Atypical presentations have been reported, including cases with prolonged or relapsing symptoms, absence of rash or arthritis, neurological involvement, or unusual laboratory findings.

While most symptomatic RRV patients recover within 4–6 weeks, some experience persistent joint or muscle pain and fatigue for months to several years. In a 1996 study of long-term symptomatic cases, at 15 months 51% of respondents still had joint pain, and 45% had persistent tiredness and lethargy¹⁵; these symptoms were still common up to 30 months after infection. Joint pain is the most common and persistent symptom, with the 4 most common joints affected being ankles (75%), wrist (72%), knees (66%) and fingers (66%). While other affected joints had much lower incidences (4-47%).¹⁶ Such cases can pose diagnostic challenges, particularly in military or deployment settings where other vector-borne or febrile illnesses are also possible.

The pathogenesis of persistent arthritis remains unclear, although persistent infection of synovial macrophages has been documented for other alphaviruses.¹⁷ RRV-induced arthritis is characterized by inflammatory infiltrates comprised largely of mononuclear cells. Characterization of those infiltrates suggests that monocytes/macrophages are a major constituent of the infiltrate, while immune-histological studies of synovial biopsy samples have also identified CD4+ and CD8+ T lymphocytes within inflammatory infiltrates.^18,19

Symptoms similar to EPA may occur after infection with Barmah Forest virus (BFV), chikungunya virus (CHIKV), Epstein-Barr virus, Rubella virus, and Parvovirus B19. BFV co-circulates with RRV in Australia with approximately 1,600 cases annually.²⁰ Currently, there is no specific antiviral treatment or vaccine for RRV. Clinical management primarily targets symptom relief.

In accordance with the Australian Health Department, definitive laboratory diagnosis of RRV infection requires specific laboratory evidence, including virus isolation or detection of viral RNA (ribonucleic acid) by RT-PCR (reverse transcription-polymerase chain reaction) in serum collected within 6 days of illness onset. Alternatively, diagnosis may be based on serological evidence, such as seroconversion or a greater than or equal to 4-fold increase in immunoglobulin G (IgG) titre, provided there is no corresponding change in antibody levels to BFV. Detection of RRV-specific immunoglobulin M (IgM) in the absence of anti-CHIKV IgM or anti-BFV IgM is also considered confirmatory evidence.

Due to serological cross-reactivity among alphaviruses, particularly BFV and CHIKV, serological diagnosis must be carefully interpreted. Alphavirus-specific IgM antibodies usually last 1–3 months, with levels generally falling subsequently.²¹ Within 2 weeks of an elevated virus-specific IgM response, a virus-specific IgG level usually becomes detectable, with IgG levels persisting for a long period, likely providing lifelong protection.²²

We report here an atypical RRV infection in 2024 in an Australian Army service member. The study was approved by the Australian Departments of Defence and Veterans’ Affairs Human Research Ethics Committee (protocol DDVA HREC P204-20). This report serves to promote awareness among medical corps and force health protection officers for consideration of deployment-related RRV disease in differential diagnosis of patients with fever, arthralgia, or rash who have recently deployed to, or conducted exercises in Australia.

Case Presentation

During a routine pre- and post-deployment serological screening program, a concerning seroconversion was identified in an Australian Defence Force (ADF) service member who had recently returned from a 3-week deployment to Papua New Guinea in late April and early May 2024. The predeployment serum sample, collected in early February 2024, was negative for anti-RRV IgG/M and neutralizing antibodies (NAb). The post-deployment serum, however, collected in early May 2024, was positive for both anti-RRV IgG/M and NAb, at a dilution of 1:320. Negative serology for anti-BFV NAb ruled out cross-reactivity and supported a definitive RRV infection.

Clinical questioning confirmed strict adherence to mosquito bite prevention measures while deployed, including sleeping indoors with screened windows, wearing a permethrin-treated uniform, and consistent use of mosquito repellent. As a result, she sustained few mosquito bites in Papua New Guinea.

Further investigation revealed that the service member resided in a known RRV hotspot in Brisbane, Queensland—an area with ongoing community transmission. The service member recalled significant mosquito exposure in early February (~15 bites per day), 2 months prior to deployment, and developed monoarthritis in the right wrist on February 13th. Imaging studies (x-ray and ultrasound) found no structural injury, and blood examination was negative for rheumatoid factors or other arthritic markers. MRI (magnetic resonance imaging) in March confirmed right wrist joint inflammation-joint effusion/synovitis (Figure 2a).

Despite the service member’s background as a laboratory scientist and personal request for RRV testing, her general practitioner dismissed the possibility of RRV infection due to monoarticular involvement.

The service member’s symptoms persisted—with manageable pain—until approximately October 2024. Some residual discomfort continued until April 2025, largely triggered by over-use. Follow-up pathology testing for rheumatoid and other arthritic markers was again negative. Additional MRI in April 2025 confirmed mild synovitis (Figure 2b), and corticosteroid injection was administered.

Based on timing, exposure history and serological data, we concluded that the infection likely occurred at the service member’s home in Queensland rather than during overseas deployment.

Discussion

Queensland is the Australian state most affected by RRV, consistently reporting over 1,000 cases annually. A record-breaking number of mosquito samples tested positive for RRV during the 2023-2024 mosquito season (November–April), which coincided with a high number of human RRV cases. Samples from more than 1,225 mosquito traps were tested, with 116 traps yielding positive results, the highest number since 2016, when the current surveillance program began. In the first 4 months of 2024, 2,065 human RRV cases were reported in Queensland, the highest total since the 2019-2020 season. In the second week of March 2024, weekly cases peaked at 333, with over 50% in Southeast Queensland, where incidence was 2.4 times higher than the 5-year average.²³

As the Indo-Pacific area becomes a defining theater of 21st century strategic competition, northern Australia, including Queensland and the Northern Territory, has emerged as a crucial area for U.S. force presence and deterrence.²⁴ U.S. military personnel who are deployed to regions where RRV is endemic, including northern Australia, Papua New Guinea, or the Solomon Islands, may be at risk of infection even during short-term exercises or visits. Exposure risk is influenced not only by location but also by timing, duration, and type of activities during deployment.

U.S. military personnel are subject to insect-borne diseases and pest threats that can adversely affect their health and compromise important missions, whether deployed in combat operations, engaged in humanitarian relief, or conducting training. Malaria, as well as flaviviruses such as dengue and West Nile virus, and alphaviruses such as RRV, BFV and CHIKV, along with sandfly fever, scrub typhus, and several tick-borne diseases, continue to pose a significant threat to forces worldwide. The largest outbreak of RRV infection ever recorded, in the Pacific from 1979 to 1980, demonstrates the epidemic potential of the virus.²⁵

The experience of Zika virus outbreaks since 2015 and the explosive CHIKV outbreak in China 2025 underscores the serious threat posed to global health by the potential for previously obscure arboviruses to shift from their historical cycles of transmission.^26,27 This risk is amplified within a mobile population such as the U.S. military.

A further risk is the potential for RRV to be exported to other countries through asymptomatic infected individuals, whether military personnel or civilians. RRV-viraemic travelers have been linked to the spread and epidemics with RRV in the Asia-Pacific region before.²⁸ This risk is of particular concern for the U.S., given the presence of mosquitoes known to be RRV vectors.^4,29

Australia remains a key partner of the U.S. in joint training operations, with an estimated 2,500 U.S. marines and sailors rotating annually through northern Australia. Additionally, in 2024, approximately 656,000 U.S. citizens traveled to Australia for recreational purposes, highlighting the potential for both military and civilian exposure to these endemic arboviruses. Enhanced surveillance, diagnostic capacity, and medical awareness of RRV, preventive measures during and after deployment must be prioritized in both the U.S. Military Health System and joint force health support planning.

This case underscores the need for heightened clinical awareness among military medical providers. U.S. service members presenting with febrile illness or joint pain after deployment to Australia should be evaluated for RRV as part of a comprehensive differential diagnosis of vector-borne diseases. Because exposure risk may extend beyond deployment sites, both deployment and travel locations should be considered when developing differential diagnoses, which should include arboviruses not endemic to Australia, such as CHIKV, dengue, and Zika virus (ZIKV). A high index of suspicion based on travel location and seasonality is needed to ensure RRV is included in the differential diagnosis.

The U.S. Department of Defence Insect Repellent System is an effective mechanism for protecting military personnel from pests and insect-borne diseases.³⁰ Preventive measures—including the use of DEET (diethyltoluamide)-based repellents, wearing long-sleeved uniforms, and treating uniforms with permethrin—remain critical to force health protection. In addition, medical staff must be aware of the local disease ecology and incorporate arboviral infections into pre-deployment briefings and post-deployment health assessments.

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Defense Health Agency. DoD Insect Repellent System. U.S. Dept. of Defense. Updated Sep. 22, 2025. Accessed Nov. 12, 2025. https://ph.health.mil/topics/entomology/pur/pages/dod-insect-repellentsystem.aspx

Author Affiliations

Australian Defense Force Malaria and Infectious Disease Institute, Gallipoli Barracks, Enoggera, Queensland, Australia: CAPT Graham, Dr. Liu, Dr. Pasay; QIMR-Berghofer Medical Research Institute, Brisbane, Queensland: CAPT Graham, Dr. Pasay; Walter Reed Army Institute of Research Engineering and Scientist Exchange Program, Enoggera: MAJ Vesely

Acknowledgments

The authors express their gratitude to all study participants, the Australian Defence Force Malaria and Infectious Disease Institute team. Special thanks to Prof. G. Dennis Shanks for his guidance and proofreading of the manuscript.

Disclaimer

The opinions and assertions contained herein are the private views of the authors authors and are not to be construed as official, nor as reflecting true views of the Australian Department of Defence or the Department of the Army. The investigators have adhered to the policies for protection of human subjects as prescribed in AR 70–25. Research data were derived from an approved Australian Department of Defence and Department of Veterans’ Affairs Human Research Ethics Committee Institutional Review Board protocol, DDVA HREC 204-20. The data are included in the manuscript. The study protocol was approved by the Australian departments of Defence and Veterans’ Affairs Human Research Ethics Committee Institutional Review Board in compliance with all applicable regulations governing the protection of human and animal subjects.

The authors declare no conflicts of interest. Joint Health Command of the Australian Defence Force funded this investigation. The funder had no role in the study design, data collection and analysis, decision to publish, or the preparation of the manuscript.

MAJ Vesely is a U.S. military service member. This work was prepared as part of official duties. Title 17, U.S. Code Section 105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S. Code Section 101 defines a U.S. Government work as a work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties.

This report has been reviewed by the Walter Reed Army Institute of Research. There is no objection to its publication.

Update: Cold weather injuries among the active and reserve components of the U.S. Armed Forces, July 2020–June 2025

Mon, 01 Dec 2025 00:00:00 Z

Abstract

From July 2024 through June 2025, a total of 806 members of the active (n=702) and reserve (n=104) components of the U.S. Armed Forces had at least 1 cold weather injury. Compared to the 2023-2024 cold season, the cold weather injury rates during the 2024-2025 cold season increased by 41.8% (from 38.6 to 54.7 per 100,000 person-years) and 45.8% (from 8.5 to 12.4 per 100,000 person-years) in the active and reserve components, respectively. The Army, Navy, and Marine Corps recorded their highest cold weather injury rates during the 2024-2025 season of the 5-year surveillance period. Frostbite was the most common cold weather injury in the Army, Navy, and Marine Corps, with the Marine Corps experiencing the largest surge in frostbite rates. Over the entire surveillance period, U.S. active component service member cold weather injury rates were generally higher among male service members, non-Hispanic Black individuals, and those under age 20 years.

What are the new findings?

The incidence rate of cold weather injuries among active component service members increased by over 40% between the 2023-2024 and 2024-2025 cold seasons, resulting in a 5-year rate of 41.5 per 100,000 person-years. This increase was primarily attributable to higher rates in the Army, Navy, and Marine Corps. The Marine Corps evinced the largest incidence rate increase (77.4%) during the 2024-2025 cold season. This year’s update expanded cold injury surveillance to include “other specified and unspecified effects of reduced temperature,” to provide a more comprehensive assessment of cold weather injuries.

What is the impact on readiness and force health protection?

Despite the terminology, cold weather injuries can occur in a variety of conditions, and in much warmer temperatures than expected, particularly during operations or training in wet or aquatic environments. It is essential that both service members and leadership understand the hazards in their environments, the risks to health, and proven prevention strategies, including weather-appropriate clothing, clean, dry socks and footwear, and proper protective gear for bodily extremities.

Background

Cold weather injuries are of significant military concern due to potential effects on service members (e.g., morbidity and potential disability) and the total force (e.g., adverse impacts on operations and costs of treatment).^1,2 In response, the U.S. Armed Forces have developed, and are continually improving, their training, doctrine, procedures, and protective equipment and clothing to counter the threat of cold environments.^3-6 Although these measures are effective when properly implemented, cold weather injuries continue to affect hundreds of service members each cold season due to exposures to both cold and wet environments.^7,8

Cold weather injuries can be broadly categorized in 2 major groups: those with a central effect and those primarily affecting the body’s periphery. Hypothermia occurs if the body cannot maintain a core temperature at or above 95°F. If skin temperatures reach 95°F, the body’s physiological response is triggered to minimize loss of heat and maintain core temperature for vital organ protection.^9,10 This response is achieved by decreasing blood flow to the extremities and redistributing warm blood to the body’s core.^9-11 Lack of blood flow to the extremities, even before a drop in core temperature, is the leading cause of peripheral cold injuries.

Initially, hypothermia may impair cognition (e.g., confusion, slurred speech, memory loss), heart rate, and breathing. Severe hypothermia can lead to loss of consciousness, pulmonary edema, coma, ventricular arrhythmias (including ventricular fibrillation), and asystole.^10,12,13 Freezing atmospheric temperatures are not required to produce hypothermia, particularly when water immersion is involved. Because heat loss occurs 2 to 5 times faster in water compared to air, core body temperature can start to drop in water temperatures as warm as 80°F.¹⁰

Peripheral cold injuries, which mainly affect the hands, feet, and face, can be further classified as either freezing injuries, such as frostbite, or non-freezing injuries, such as immersion foot. Freezing peripheral injury is defined as the damage sustained by tissues when skin temperatures fall below freezing, most frequently affecting tissues of the ears, nose, cheeks, chin, fingers, and toes.^10,11,14-16 A substantial proportion of patients with peripheral frostbite experience permanent changes in microcirculation and disruption of localized nerve functions (e.g., reduced sensation in affected area).15 Although most frostbite damage is minor, severe injury may lead to impaired functioning and inability to perform occupational tasks due to hypersensitivity to cold, chronic ulceration, vasospasm, localized osteoarthritis, or chronic pain.^11,15,17

Non-freezing peripheral injury includes a spectrum of localized injuries to the soft tissues, nerves, and vasculature of distal extremities that result from prolonged exposure to wet, cold (generally 32–59°F) conditions; the injury process is generally slower in warmer water.^10,11,14,18 Although most non-freezing peripheral injuries involve feet, any body part can be affected by the condition, including hands.¹⁹ When immersion foot injury occurs, the foot becomes hyperemic (i.e., increased blood flow), painful, and swollen with continuous exposure; progression to blistering, decreased blood flow, ulceration, and gangrene is gradual.^11,18,20

Environmental factors that increase risk of cold weather injury include specific geographic locations including high altitudes, prolonged outdoor exposure to temperatures 40°F and lower, wind speeds exceeding 5 miles per hour, wet conditions due to rain or snow, or submersion in cold water, in addition to lack of adequate shelter and clothing.¹⁹ Situational factors that increase risk of immersion foot include immobility, wet socks, and constrictive footwear.^20-22 Individual risk factors vary and include prior cold weather injury, improper acclimatization, dehydration, fatigue, inadequate nutrition, alcohol use, smoking, medications that impair compensatory responses (e.g., oral anti-hyperglycemics, beta-blockers, general anesthetic agents), and chronic disease (e.g., peripheral vascular disease, diabetes).^{10,11,16,20-22}

Continuous surveillance of cold weather injuries is essential to understand the magnitude of risk they pose, inform prevention efforts, and remind leaders of the hazards of training and operating in wet and cold environments. Department of Defense guidelines for reportable medical events (RMEs) require reporting of cases of hypothermia, freezing peripheral injuries (e.g., frostbite), and non-freezing peripheral injuries (e.g., immersion injuries, chilblains).²³

Since 2004, MSMR has published annual updates on the incidence of cold weather injuries affecting U.S. Armed Force members for the 5 most recent cold seasons.²⁴ The timing of these annual updates is intended to call attention to the recurring risks of such injuries as winter approaches in the Northern Hemisphere, where most members of the U.S. Armed Forces are assigned. Following a period of more limited scope, this update restored expanded cold weather injury surveillance last reported in 2017.²⁵ The current report now includes—in addition to frostbite, immersion injury, and hypothermia—unspecified cold injuries with “other effects of reduced temperature” for more complete case ascertainment.

Methods

This surveillance population included all individuals who served in the active or reserve components of the U.S. Armed Forces at any time during the surveillance period of July 1, 2020 through June 30, 2025. For analysis purposes, a cold season was defined as July 1 through June 30 intervals, to allow for complete representation of cold weather seasons with annual summaries and appropriate comparisons. Due to data availability that began in January 2023, Space Force service members were classified separately starting in the 2022-2023 cold season; previously they were classified as Air Force.

Records of cold weather injuries for freezing peripheral injuries (i.e., frostbite), non-freezing peripheral injuries (i.e., immersion hand, foot injuries), hypothermia, and unspecified cold weather injuries were identified from 2 sources: 1) RMEs submitted to the Disease Reporting System internet (DRSi) and 2) diagnostic codes from inpatient and outpatient medical encounters in the Defense Medical Surveillance System and in-theater records from the Theater Medical Data Store (which maintains electronic records of medical encounters of deployed service members). A cold weather injury case was defined by the presence of an RME or 1 of any of the following qualifying International Classification of Diseases, 10th Revision (ICD-10) codes in the first diagnostic position of an encounter for frostbite (T33*, T34*), immersion injury (T69.0*), hypothermia (T68*), or other effects of reduced temperature (T69.8, T69.9). Additional analyses were conducted to examine the distribution of cold injury types by services to further assess trends.

To estimate the number of unique individuals who experienced a cold weather injury each cold season, and to avoid inclusion of follow-up health care encounters, only 1 cold weather injury per individual per season was included in the counts of ‘any cold weather injury’. For analyses of specific cold weather injury types (frostbite, immersion injury, hypothermia, unspecified), individuals could contribute a maximum of 1 case per cold weather injury type per season to the ‘all cold weather injuries’ count. For example, if an individual was diagnosed or reported with an immersion injury at 1 point during a cold season, then with frostbite later in the same cold season, each different injury type would be included in injury-specific calculations. If a service member had multiple medical encounters for the same cold weather injury, only 1 encounter was included in this analysis. Hospitalization encounters were prioritized over ambulatory health care visits.

Annual seasonal incidence rates (IRs) of cold weather injuries among active component service members (ACSMs) were calculated as incident cold weather injury diagnoses per 100,000 person-years (p-yrs) of service. Annual seasonal IRs of cold weather injuries among reservists were calculated as cases per 100,000 persons, using the total number of reserve component service members for each cold season of the surveillance period. Person counts were used as the denominator for reserve component because the lack of start and end dates for active duty service periods precluded accurate person-time calculation.

Cold weather injuries are summarized by the locations where service members were treated for those injuries, identified by a Defense Medical Information System Identifier (DMIS ID) of a health care encounter. Because such injuries can occur during field training, temporary duty, or outside usual duty stations, DMIS IDs were utilized as proxies for locations where cold weather injuries occurred.

Results

2024–2025 cold season

From July 2024 through June 2025, a total of 806 members of the active (n=702) and reserve (n=104) components of the U.S. Armed Forces had at least 1 cold weather injury (Table 1).

In the active component, Army members had the highest rate of any cold weather injury (n=417, 95.5 per 100,000 p-yrs) during the 2024-2025 cold season, followed by members of the Marine Corps (n=147, 88.7 per 100,000 p-yrs), Air Force (n=85, 27.6 per 100,000 p-yrs), and Navy (n=48, 14.8 per 100,000 p-yrs). One active component Space Force member (10.6 per 100,000 p-yrs) and 4 active component Coast Guard members (10.0 per 100,000 p-yrs) were affected by cold weather injuries during the 2024-2025 cold season (Table 1, Figure 1). Within the reserve component, Army personnel accounted for 77.9% of the cold injury cases (n=81, 14.7 per 100,000 persons) in the 2024-2025 cold season (Table 1, Figure 2), although reservists in the Marine Corps (n=8, 20.6 per 100,000 persons) had higher rates of cold weather injuries.

Frostbite was the most common type of cold weather injury among active component Army (n=167, 35.1%, Table 2a), Marine Corps (n=63, 40.1%, Table 2d) and Air Force (n=49, 53.3%, Table 2c) members in 2024-2025, whereas immersion injury (n=15, 30.6%) and hypothermia (n=15, 30.6%) were the most common types of cold weather injuries among Navy service members (Table 2b).

Five cold seasons: July 2020–June 2025

The crude IR for all 5 cold seasons of any cold weather injury was 41.5 per 100,000 p-yrs for all ACSMs (Table 1). In the most recent cold season, 2024-2025, the crude IR of any cold weather injury for all ACSMs increased by 41.8%, from 38.6 per 100,000 p-yrs in 2023-2024 to 54.7 per 100,000 p-yrs in 2024-2025 (Table 1), the highest value documented during the 5-year surveillance period. Similarly, the crude IR of any cold weather injury for the reserve component increased by 45.8% in 2024-2025 (from 8.5 to 12.4 per 100,000 persons) from the prior season. Throughout the surveillance period, cold weather injury rates remained consistently higher among ACSMs in the Army and Marine Corps (Figure 1).

During the 5-year surveillance period, overall rates of all cold weather injuries in the active component were generally higher among service members who were male (except in the Marine Corps), non-Hispanic Black individuals, and among the 2 youngest age groups (ages <20 and 20-24 years) (Tables 2a–2d). When specific types of cold injury were considered, male and non-Hispanic Black service members had higher rates of frostbite in comparison to other types of injury (Tables 2a–2d). Among all cold weather injury cases reported within the active component during the 5-year period, the Marine Corps demonstrated the highest recruit cold weather injury rate (238.7 per 100,000 p-yrs). With the exception of the Marine Corps, enlisted personnel had higher rates of cold weather injury compared to officers (Tables 2a–2f).

Throughout the 5-year surveillance period, a total of 38 ACSMs (1.4% of total) were hospitalized. The Army (n=25) and Marine Corps (n=8) accounted for the majority (86.8%) of hospitalized cases (data not shown).

Patterns and trends in service branches

Army

Within the Army active component, total cold injury cases and IRs increased from 356 cases (74.6 per 100,000) in 2020-2021 to 476 cases (109.0 per 100,000) in 2024-2025, representing a 46.1% increase during the surveillance period (Table 2a, Figure 3a). Frostbite was the most common cold injury type overall, with rates increasing by 35.4% in 2024-2025 compared to the prior season. Army IRs increased most for unspecified injuries, with values nearly tripling over the surveillance period (from 11.9 to 33.7 per 100,000 p-yrs). Increases in immersion injuries and hypothermia were slight-to-moderate and less pronounced.

Navy

Among the Navy active component, total cases and IRs increased from 30 cases (8.8 per 100,000 p-yrs) in 2020-2021 to 49 (15.1 per 100,000 p-yrs) in 2024-2025, representing a 71.6% IR increase over the surveillance period (Table 2b, Figure 3b). The overall increase for the Navy was primarily driven by comparatively sharp rises in immersion injuries and hypothermia cases in 2024-2025, compared to prior seasons. The highest IR for the Navy during the 5-year surveillance period was seen for frostbite cases, followed closely by hypothermia. Counts and IRs of unspecified injuries were relatively lower and fluctuated over the surveillance period.

Air Force

Within the Air Force active component, total cold injury cases and IRs increased from 71 cases (21.6 per 100,000 p-yrs) in 2020-2021 to 92 (29.9 per 100,000 p-yrs) in 2024-2025 (38.4% IR increase), with the apex (100 cases, 31.9 per 100,000 p-yrs) during the 2023-2024 cold season (Table 2c, Figure 3c). The observed Air Force increase was largely attributable to rises in immersion injuries and hypothermia cases. Rates of unspecified injuries, the second most common cold injury following frostbite, fluctuated throughout the surveillance period.

Marine Corps

Among the Marine Corps active component, total cold injury cases and IRs increased from 114 cases (63.3 per 100,000 p-yrs) in 2020-2021 to 157 cases (94.8 per 100,000 p-yrs) in 2024-2025, representing a 49.8% increase during the surveillance period (Table 2d, Figure 3d). Frostbite was the dominant cold injury, in both counts and IRs. Frostbite IRs in the Marine Corps nearly tripled during the most recent cold season compared to the prior season (38.0 per 100,000 p-yrs in 2024-2025 vs. 13.7 in 2023-2024). Immersion injuries and hypothermia also showed notable increases over time within the Marine Corps, while unspecified injuries, although smaller in magnitude, also rose sharply in the 2024-2025 cold season.

Deployment-related cold weather injuries

During the 5-year surveillance period, a total of 82 cold weather injuries were diagnosed among service members deployed outside the U.S. (data not shown), of which 35 (42.7%) were frostbite, 33 (40.2%) were immersion injuries, 12 (14.6%) were hypothermia, and 2 (2.4%) were unspecified. Among the 28 cases of the 82 total deployment-associated cold weather injuries diagnosed during the 2024-2025 cold season, 17 were frostbite, 7 were immersion injuries, and 4 were hypothermia cases.

Geographic locations of cold weather injuries

During the 5-year surveillance period, 23 military locations reported at least 25 incidents of cold weather injury (1 per person per cold season) among ACSMs. Figure 4 charts the 2024-2025 seasonal numbers of cold weather injuries (1 per person per year) for each of those 23 locations, in addition to the median case numbers for the previous 4 cold seasons. The highest 5-year counts of incident cold weather injuries for seasons 2020 through 2025 were recorded at Fort Wainwright, Arkansas (n=335), Joint Base Elmendorf-Richardson, Arkansas (n=209), Marine Corps Base Camp Lejeune, North Carolina (n=115), Fort Carson, Colorado (n=104), and U.S. Army Garrison Bavaria, Germany (n=85) (data not shown).

Discussion

Overall rates peaked in 2024-2025 for any cold weather injury among the U.S. active and reserve components, increasing by 41.8% and 45.8%, respectively, from the 2023-2024 season. During the 5-year surveillance period, the active components of all services experienced increased IRs for cold injuries. During the 2024-2025 cold season, the Army, Navy, and Marine Corps active components experienced their highest rates of any cold weather injury for the entire 5-year surveillance period. The Coast Guard and Space Force average less than 5 cases per year among their ACSMs, thus, small changes in the numbers of cases annually will result in abnormally large fluctuations in the injury rate. Frostbite was the most common cold weather injury in the Army, Marine Corps, and Navy, while the Marine Corps saw the largest surge in frostbite rates. In contrast, immersion injuries and hypothermia were the main causes of increases in the Navy and Air Force. Rates of unspecified cold injuries also increased substantially within the Army and Marine Corps, but remained lower and more variable in the Navy and Air Force.

The simultaneous increase in both specific and unspecified case rates suggests true increases in cold weather injury occurrence in the 2024-2025 cold season. The increase in IRs could indicate heightened exposure to environmental risk factors. The long-term complications of non-freezing injuries are similar to, and equally debilitating as, those produced by frostbite: hypersensitivity to cold, chronic pain, and severe pain induced by walking.^17,18,20

Similar to previous MSMR reports, the highest cold weather injury rates were observed among service members who were male, those in younger age groups, and non-Hispanic Black individuals.^8,24 Increasing rates of cold weather injury have also been noted among service members in the United Kingdom (U.K.) military with similar demographic characteristics.^21,26,27 Differences in physiological responses to cold stress have been observed between various racial and ethnic groups, with individuals of African descent demonstrating greater vasoconstriction responses compared to individuals of Asian or Caucasian descent.^10,15,28 Signs and symptoms of cold weather injury (e.g., skin redness, blotchy skin) may initially be more difficult to see on service members with skin of darker color.^29,30 Service members, leadership, and medical personnel should be educated on the early signs and symptoms of cold weather injuries for a wide range of skin types.

When examining the demographic groups with increased rates within the services, it should be noted that there were differences in the most frequently observed cold weather injury types. Younger marines had higher rates of immersion injuries, while younger soldiers had higher rates of frostbite. Such differences could indicate different situational risk factors, such as specific training activities, occupational tasks, and geographic regions, for cold weather injury among the service branches. A study of U.K. service personnel noted that the most common situational risk factors for non-freezing peripheral injury were standing guard, as well as wet socks and boots.²¹ Unit leaders must be able to assess environmental, situational, and individual risk factors of their training and operational environments and understand how those factors increase risk of cold weather injuries for service members in their charge.

This analysis of cold weather injuries was unable to distinguish between injuries sustained during official military duties (e.g., training or operations) and those associated with unrelated or personal activities. This report expanded the scope of cold injuries beyond specified conditions (e.g., frostbite, immersion injury, hypothermia) to include “other specified and unspecified effects of reduced temperature.” That change contributed to an increased overall case count compared to last year’s report. The increase in cold injury IRs was observed uniformly for all services and specific injury types, suggesting a genuine rise in cold injury incidence rather than solely an artifact of broadened inclusion criteria.

Cold weather injuries can be prevented by ensuring proper clothing, including layers that can be added or removed according to environmental conditions and specific physical activities, along with footwear that is non-constrictive, dry, and regularly changed if wet.^9,10,22 Proper hydration and nutrition, avoidance of long periods of sedentary or immobile positions, and planning for appropriate shelter and opportunities for re-warming are also important.

Military training or mission requirements in cold and wet weather conditions can preclude immediate warm or dry shelter, ability to change wet or damp clothing, or even healthy physical activity.^2,3,11 To prepare for all circumstances posing a threat for cold weather injury, service members should be cognizant of, and able to identify, signs of cold weather injury in addition to environmental, individual, and situational risk factors. Service members should also be aware of protective measures for themselves and their fellow service members, whether during training, operations, combat, or recreational activities in wet or freezing conditions.

Acknowledgment

The editors would like to thank Erika Dreyer, MPH, Epidemiology and Analysis Branch, Armed Forces Health Surveillance Division, for analyzing the data presented in this report.

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Headquarters, Department of the Army. Technical Bulletin Medical 508. Technical Bulletin: Prevention and Management of Cold-Weather Injuries. U.S. Dept. of Defense. Apr. 1, 2005. Accessed Nov. 6, 2025. https://apps.dtic.mil/sti/tr/pdf/ADA433435.pdf
U.S. Army Training and Doctrine Command Headquarters, Department of the Army. TRADOC Regulation 350-29. Training: Prevention of Heat and Cold Casualties. U.S. Dept. of Defense. Jun. 15, 2023. Accessed Nov. 6, 2025. https://adminpubs.tradoc.army.mil/regulations/tr350-29.pdf
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Maley MJ, Eglin CM, House JR, Tipton MJ. The effect of ethnicity on the vascular responses to cold exposure of the extremities. Eur J Appl Physiol. 2014;114(11):2369-2379. doi:10.1007/s00421-014-2962-2
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Update: Diagnoses of mental health disorders among U.S. active component service members, 2020–2024

Mon, 01 Dec 2025 00:00:00 Z

Abstract

Mental health disorders have long been recognized as a problem in a wide range of domains, including the military, resulting in significant impacts on general morbidity, health care provision, disability, and military discharges. From 2020 through 2024, a total of 560,035 U.S. active component service members were diagnosed with at least 1 mental health disorder. Annual incidence rates of mental health disorder increased steadily from 2020 until 2022, but adjustment disorder decreased since then, anxiety gradually increased, and the remaining conditions remained relatively unchanged. Most mental health disorder diagnoses were attributable to adjustment disorders, anxiety disorders, depressive disorders, post-traumatic stress disorder, alcohol-related disorder, and other mental health disorders. Historically, mental health disorders have often been misunderstood and stigmatized, leading to under-reporting, delayed treatment, and poor prognoses. Reflecting the unique stressors and cultural stigmas of military life, ongoing efforts to raise awareness, encourage help-seeking, and improve treatment options are essential to supporting the mental and emotional well-being of service members.

What are the new findings?

While the incidence of U.S. service members who were diagnosed with at least 1 mental health disorder remained stable from 2023 to 2024, the annual incidence rate of anxiety disorders demonstrated a continual increase from 2020 to 2024.

What is the impact on readiness and force health protection?

The sustained incidence of mental health disorders (11,534.1 per 100,000 person-years) diagnosed among U.S. active component service members in addition to significant variations in relation to sex, service branch, occupation, and length of military service, underscores the need for targeted interventions along with continued monitoring to ensure force readiness.

Background

Mental health is a significant public health issue for the U.S. military due to the unique stressors experienced by service members. Military service, especially deployment, is linked to higher rates of mental health issues both during and after service. While combat and deployments are major risk factors, even general military service can lead to mental health challenges. Mental health issues can manifest at any time but are particularly prevalent when individuals are in close proximity to combat situations or during the transition from active duty to civilian life.¹

In 2024, mental health disorders accounted for the largest total number of hospital bed days and second highest total number of medical encounters for members of the active component of the U.S. Armed Forces.² In general, incidence rates (IRs) of mental health disorders have been observed to be highest among Army soldiers, female service members, and those in younger age groups.^3-6 The most recent MSMR update on mental health disorders, in 2024, found the IR of any mental health diagnosis increased by almost 40% between 2019 and 2023, largely attributable to adjustment disorders, anxiety disorders, depressive disorders, post-traumatic stress disorder (PTSD), alcohol-related disorders, as well as ‘other’ mental health disorders.⁶ Mental health disorders often co-occur with other conditions, making professional diagnosis and personalized treatment plans crucial.

Despite the high prevalence and severity of mental health issues during military service, service members face challenges in accessing mental health treatment due to constraints including deployment, frequent relocation, limited mental health service capacity, and stigma associated with seeking care.⁷ Addressing mental health disorders in military service members necessitates increased awareness, expanded access to care, and a prioritized focus on evidence-based treatments. Due to the significant impacts of mental health issues, military leaders, policy-makers, researchers, and the public are urging governments to provide timely and appropriate mental health services to service members.¹ This report summarizes the numbers, types, and IRs of mental health disorder diagnoses among U.S. active component service members (ACSMs) over a 5-year surveillance period, 2020 through 2024.

Methods

The surveillance period for this report included January 1, 2020 through December 31, 2024. The surveillance population included all individuals who served in the active components of the U.S. Army, Navy, Air Force, Marine Corps, Coast Guard, or Space Force, at any time during the surveillance period. Due to Space Force personnel data availability for 2023 only, Space Force service members were combined with Air Force personnel for this analysis.

All data used to determine mental health diagnoses were derived from records routinely maintained in the Defense Medical Surveillance System (DMSS). DMSS records document both ambulatory health care encounters and hospitalizations of active component members of the U.S. Armed Forces in fixed military and civilian (if reimbursed through the Military Health System, or MHS) hospitals and clinics. Diagnoses were also derived from records of medical encounters of deployed service members documented in the Theater Medical Data Store (TMDS) in DMSS.

For purposes of analysis, mental health disorders were ascertained from records of medical encounters that included mental health disorder-specific diagnoses with International Classification of Diseases, 9th and 10th revisions (ICD-9/ICD-10) codes (ICD-9: 290–319; ICD-10: F01–F99) (Table 1) in the first or second diagnostic position. Although the MHS transitioned to ICD-10 coding on October 1, 2015, ICD-9 codes were included in this analysis, as some TMDS encounters still contain ICD-9 diagnoses, which were needed to identify and exclude prevalent cases in records before October 1, 2015. Diagnoses of pervasive developmental disorder (ICD-9: 299.*; ICD-10: F84.*), specific delays in development (ICD-9: 315.*; ICD-10: F80.*–F82.*, F88–F89), mental retardation (ICD-9: 317.*–319.*; ICD-10: F70–F79), tobacco use disorder and nicotine dependence (ICD-9: 305.1; ICD-10: F17.*), and post-concussion syndrome (ICD-9: 310.2; ICD-10: F07.81) were excluded from analysis.

Each incident diagnosis of a mental health disorder was defined using the corresponding Armed Forces Health Surveillance Case Definition.⁵ For most mental health disorders, a case was defined by either a hospitalization with an indicator diagnosis in the first or second diagnostic position; 2 outpatient or TMDS visits within 180 days documented with indicator diagnoses (from the same mental health disorder category) in the first or second diagnostic position; or a single outpatient visit in a psychiatric or mental health care specialty setting (defined by Medical Expense and Performance Reporting System [MEPRS] code beginning with ‘BF’) with an indicator diagnosis in the first or second diagnostic position.

The surveillance case definitions for schizophrenia, acute stress disorder, and eating disorders included some exceptions to the case parameters described. The case definition for schizophrenia required either a single hospitalization with a diagnosis of schizophrenia in the first or second diagnostic position or 4 outpatient or TMDS encounters with a diagnosis of schizophrenia in the first or second diagnostic position. Schizophrenia cases who remained in the military for more than 2 years after becoming incident cases were excluded, as those cases were assumed to have been mis-diagnosed. The case definition for acute stress disorders required 1 encounter with an indicator diagnosis in any diagnostic position, due to the transient nature of its symptoms. Eating disorder cases required 1 inpatient encounter with an indicator diagnosis in the first or second diagnostic position, or a single outpatient or TMDS encounter with an indicator diagnosis in the primary diagnostic position.

Service members diagnosed with 1 or more mental health disorders before the surveillance period (i.e., prevalent cases) were not considered at risk of incident diagnoses of the same conditions during the period. Service members diagnosed with more than 1 mental health disorder during the surveillance period were considered incident cases in each category in which they fulfilled the case-defining criteria. Service members could be considered incident cases only once in each specific mental health disorder category.

Results

Numbers and incidence rates of mental health diagnoses

During the 5-year surveillance period, 560,035 ACSMs were diagnosed with at least 1 mental health disorder; of those individuals, 268,480 (47.9%) were diagnosed with mental health disorders in more than 1 diagnostic category (Table 2). Overall, 1,007,037 incident diagnoses of mental health disorders were recorded in all diagnostic categories. The annual IRs of at least 1 mental health disorder increased from 8,430.2 per 100,000 person-years (p-yrs) in 2020 to 11,679.0 per 100,000 p-yrs in 2023, then decreased slightly to 11,534.1 per 100,000 p-yrs in 2024 (Table 2).

Over the entire surveillance period, 95% of all incident mental health disorder diagnoses were attributable to adjustment disorders (n=282,883, 28.1%), anxiety disorders (n=208,217, 20.7%), depression disorders (n=177,483, 17.6%), ‘other’ mental health disorders (n=124,142, 12.3%), PTSD (n=95,189, 9.5%), and alcohol-related disorders (n=69,248, 6.9%) (Table 2). In comparison, a relatively small number of incident diagnoses of personality disorders (n=15,668, 1.6%), substance-related disorders (n=15,275, 1.5%), bipolar disorder (n=8,654, 0.9%), other psychoses (n=3,838, 0.4%), eating disorders (n=3,678, 0.4%), schizophrenia (n=1,475, 0.1%), acute stress disorders, (n=1,191, 0.1%), and factitious disorders (n=96, 0.01%) contributed to the incident diagnoses of mental health disorders among ACSMs.

Annual IRs for adjustment disorders, alcohol-related disorder, personality disorders, substance-related disorder, bipolar disorder, eating disorders, and acute stress disorder increased steadily from 2020 until 2022 but then decreased, with adjustment disorders decreasing considerably thereafter. In contrast, anxiety increased gradually and steadily over the 5-year surveillance period, while conditions including depression, other mental health disorders, PTSD, other psychoses, and schizophrenia fluctuated (Table 2).

Co-occurring mental health diagnoses

Individuals with mental health disorders are often diagnosed with more than 1 mental health disorder. During the surveillance period, adjustment disorders were often co-diagnosed with other disorders, with 35.7% of substance-related disorders and 59.8% of personality disorders co-diagnosed with adjustment disorders.

Incident Diagnoses per 100,000 p-yrs

Depressive disorders were also often co-diagnosed with all other mental health disorders, ranging from 26.7% of substance-related disorder cases with co-diagnoses to 59.9% of bipolar disorder diagnoses. Incident cases of anxiety disorders were also co-diagnosed with factitious disorders (51.0%), bipolar disorder (47.3%), depressive disorders (46.0%), eating disorders (44.8%), PTSD (41.7%), personality disorders (41.3%), and acute stress disorder (36.4%) (Table 3).

Incidence rates of mental health diagnoses by sex

In general, most incident mental health disorder diagnoses were more prevalent among female service members, but alcohol- and substance-related disorders were more prevalent in male service members during the 5-year surveillance period. Schizophrenia was diagnosed at a higher rate in male service members in 2024 and 2020 (Figures 1a–2b).

Rates of mental health disorder diagnoses in male service members steadily increased until 2022, remaining relatively unchanged since then, with the exception of decreases in adjustment disorders, substance-related disorders, and personality disorders. Anxiety disorders increased throughout the surveillance period among male service members (Figures 1a, 1b).

Rates of mental health disorder diagnoses in female service members followed a similar pattern to those of male service members, with the exception of a slight decrease in anxiety disorders in 2024. Adjustment disorder IRs were the highest among women in 2024, followed by anxiety disorders, depressive disorders, other mental health disorders, and PTSD. During the 5-year surveillance period, eating disorders were 7–10 times more common in female ACSMs than in males, while personality disorders were 3.2–3.6 times more common among women (Figures 2a, 2b).

Incidence rates of mental health diagnoses by age

Rates of most mental health disorders varied by age, with adjustment disorders exhibiting the highest incidence among all age groups (Figure 3). Service members under age 20 years had the highest IR of adjustment disorder, compared to all other age groups. Rates of alcohol- and substance-related disorders, along with personality disorders, bipolar disorder, eating disorders, and schizophrenia, were highest for service members aged 20-24 years, while declining thereafter with increasing age. As age increased, PTSD increased, while adjustment disorders, anxiety disorders, depressive disorders, and acute stress disorders fluctuated. ACSMs ages 40-49-years had the highest IRs of anxiety and depressive disorders, and those older than age 50 years had the highest incidence of PTSD. After age 30 years, rates of adjustment disorders, anxiety disorders, and depressive disorders increased until ages 40-49 years, thereafter declining in those older than age 50 years.

Incidence rates of mental health diagnoses by service

Overall, IRs of mental health disorders were highest in the Army, specifically adjustment disorders, alcohol-related disorders, substance related disorders, anxiety disorders, PTSD, schizophrenia, other psychoses, and eating disorders. The Navy accounted for the highest IRs of depressive disorders, personality disorders, and bipolar disorder, while the Coast Guard accounted for the highest IRs of acute stress disorders (Figure 4).

Incidence rates of mental health diagnoses by occupation

Rates of adjustment disorders, anxiety disorders, depressive disorders, PTSD, personality disorders, bipolar disorder, eating disorders, and acute stress disorders were generally highest in health care occupations. Service members in combat-related roles exhibited the highest IRs of alcohol- and substance-related disorders, while those in motor transport had the highest rates of other psychoses and schizophrenia. By contrast, pilots and air crew personnel showed the lowest IRs of mental health disorders (Figure 5).

Incidence rates of mental health diagnoses by time in service

Rates of mental health disorder diagnoses differ by length of service, with highest IRs of schizophrenia, other psychoses, and acute stress disorders diagnoses occurring among ACSMs with less than 6 months of service. For those who served 12-36 months, the most common diagnoses were adjustment disorders, alcohol-related disorders, substance-related disorders, personality disorders, bipolar disorder, and eating disorders. Among those who served 36 months or longer, anxiety disorders, depressive disorders, and PTSD were most common (Figure 6).

Discussion

This report provides an update on incident diagnoses for mental health disorders among ACSMs of the U.S. Armed Forces from 2020 through 2024. Adjustment disorders, anxiety disorders, depressive disorders, PTSD, and alcohol-related disorder, along with other mental health disorders, consistently accounted for approximately 95% of all mental health disorder diagnoses during the 5-year surveillance period. IRs of anxiety disorders increased substantially from 2020 to 2024.

The increasing incidence of anxiety disorders and PTSD among ACSMs is complex, with multiple contributing factors including combat exposure, military culture and environment, personal and pre-existing factors, in addition to other stressors.^8,9 The consequences of these disorders can affect service readiness, military occupations, professional and personal relationships, long-term health, substance use, and potential suicidal ideation.¹⁰

Prior MSMR reports indicate that approximately one-third of anxiety disorder diagnoses from 2000 to 2011 had a co-occurring diagnosis of either adjustment or depressive disorder.¹¹ Co-occurring diagnoses persist in this report, which documents both adjustment disorders (42.1%) and depressive disorders (39.2%) as the leading 2 co-occurring diagnoses, from 2020 through 2024, for ACSMs with incident anxiety disorder diagnoses. Co-occurring mental health diagnoses represent a significant challenge, as they can increase both the complexity and severity of symptomology, complicate diagnosis and treatment, and affect overall prognosis. Mental health disorders affect male and female service members differently, with effects on both related prevalence and presentation of mental health conditions. During the 5-year surveillance period, most mental health disorders were more prevalent among female ACSMs, while alcohol and substance-related disorders were more common among male ACSMs. Female service members’ vulnerability to physical and mental health issues appears to be highly correlated with unwanted gender-based experiences, which may lead them more likely to report mental health problems than male service members.¹² In particular, the IR of eating disorders among female service members in this report was 7–10 times higher than that of male service members, similar to the results of a previous report.¹³ Eating disorders are complex conditions, difficult to treat and often co-occurring with other mental health conditions, making understanding each individual’s unique needs and experiences crucial for effective treatment.¹⁴ Differences in mental health disorder diagnoses between the sexes underscores the need for individualized treatment approaches that are sex-specific.

Consistent with previous findings, this report confirms age-related variations in mental health diagnoses, with service members aged 20-24 years exhibiting a particularly high incidence of mental health disorders during the 2020–2024 surveillance period.^3,15 While IRs varied by age group, each age group exhibited mental health problems that were particularly severe and unique to that age group.

From 2020 through 2024, the Army consistently reported higher IRs of most mental health disorders, likely due to its large size, frequent deployments, and high-stress missions.^6,15 While the Army has higher IRs overall, the Marine Corps is often viewed as the most mentally demanding branch due to its rigorous standards and intense emotional and psychological pressures.¹⁶ Effective management and prevention must take into account each branch of service’s distinct demographics, culture and missions, in order to fully address mental health.

As documented in a prior report,⁶ service members in health care occupations exhibited higher rates of diagnoses of most mental health disorders. Health care professionals often struggle to provide appropriate care for themselves, and when mental illness develops, tend to be reluctant to seek help when needed and neglect self-care.¹⁷ The higher rates of mental health disorders among those in health care occupations suggest an important need for future research on effective solutions to support the mental health of military health care personnel.

During the 5-year surveillance period, adjustment disorders generally had highest incidence rates during the early stages of military service. All mental health disorders continued to increase until mid-career, after which all mental health disorders decreased or remained stable through the later career stages, with the exception of anxiety disorders and PTSD.

There are several limitations in interpreting the results in this report. First, this report was compiled based on standardized administrative records and may not be reliable indicators of the true burden of mental health disorders among military service members. Second, this report may under-estimate the incidence of mental health disorders if service members do not seek appropriate care or receive care not routinely documented as ICD-9/ICD-10-coded diagnoses (e.g., from private practitioners, counseling or advocacy support centers, chaplains), or if mental health disorders were not diagnosed or reported on standardized records of care, or if diagnoses were mis-coded or incorrectly transcribed on centrally transmitted records. Conversely, some conditions may have been erroneously diagnosed or mis-coded as mental health disorders (e.g., screening visits), which may contribute to an over-estimation of the true burden of disease. Lastly, these analyses summarize the experiences of individuals while serving in an active component of the U.S. military and do not include mental health disorders or problems that affected members of reserve components or veterans of recent military service who received care outside the MHS.

In September 2024, the Department of Defense revised Instruction 6490.08, establishing a Department policy that promotes health-seeking behaviors for mental health services. The new policy emphasizes unrestricted, non-stigmatizing access to mental health care services, including voluntary substance mis-use education, as essential for maintaining the health and readiness of the total force.¹⁸ As the burden of mental health disorders continues to increase during a period of policy change, ongoing surveillance and further analyses are warranted to better understand the true burden of disease in addition to health care access and provision. The results from this report underscore the need for mental health services to address a range of mental health co-morbidities in ACSMs.

Mental health stigma is a primary barrier to help-seeking in the military, consistently identified as a major concern in military studies.¹⁹ Although stigma’s direct effect on care may be minimal,²⁰ a holistic approach that comprehensively addresses the complex needs of military personnel is crucial, providing integrated care from military and civilian providers that proactively works to reduce the persistent stigma associated with seeking mental health support.^21,22

The trends in this report demonstrate the ongoing need for mental health services among U.S. military members, documented in previous MSMR reports. Effectively addressing the increasing rates of anxiety disorders and PTSD in ACSMs requires evidence-informed prevention strategies, enhanced access to care, early intervention, appropriate and integrated treatment, strengthened support networks, along with ongoing research.¹ In addition, effective management of co-occurring disorders requires comprehensive assessment approaches complemented by treatment plans that are both individualized and integrated.^8,23

Acknowledgment

The editors would like to thank Jessica H. Murray, MPH, Epidemiologist, Epidemiology and Analysis Branch, Armed Forces Health Surveillance Division, for analyzing the data presented in this report.

References

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Armenta R, Rush T, LeardMann CA. et al. Factors associated with persistent posttraumatic stress disorder among U.S. military service members and veterans. BMC Psychiatry. 2018;18(1):48. doi:10.1186/s12888-018-1590-5
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Tedla A, Asnakew S, Legas G, et al. Post-traumatic stress disorder among military personnel admitted at the Northwest Command level three military hospital, Bahir Dar, Ethiopia, 2022: an institution-based cross-sectional study. Front Psychiatry. 2024;15:1410630. doi:10.3389/fpsyt.2024.1410630
Armed Forces Health Surveillance Center. Anxiety disorders, active component, U.S. Armed Forces, 2000–2012. MSMR. 2013;20(10):2-6. Accessed Nov. 20, 2025. https://www.health.mil/reference-center/reports/2013/01/01/medical-surveillance-monthly-report-volume-20-number-10
Jaycox LH, Morral AR, Street A, et al. Gender differences in health among U.S. service members: unwanted gender-based experiences as an explanatory factor. Rand Health Q. 2023;10(2):8. Accessed Nov. 20, 2025. https://pmc.ncbi.nlm.nih.gov/articles/pmc10187550
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Piro L, Luo H, Jones K, et al. Racial and ethnic differences among active-duty service members in use of mental health care and perceived mental health stigma: results from the 2018 Health Related Behaviors Survey. Prev Chronic Dis. 2023;20:e85. doi:10.5888/pcd20.220419
Yule AM, Kelly JF. Integrating treatment for co-occurring mental health conditions. Alcohol Res. 2019;40(1):arcr.v40.1.07. doi:10.35946/arcr.v40.1.07

Trends in the prevalence of obesity among U.S. active component service members and civilians, 2013–2023

Mon, 01 Dec 2025 00:00:00 Z

Abstract

Trends in obesity among U.S. active component service members (ACSMs) and civilians are relevant to military recruitment and retention, as excess body weight is a common disqualification for military service. This study utilized measured height and weight data from the Military Health System Data Repository for ACSMs (cumulative n=12,262,745) and the National Health and Nutrition Examination Survey for civilians ages 17-62 years (cumulative n=19,334). Accounting for the design of each data source, the prevalence of obesity (body mass index≥30 kg/m²) and body mass index (BMI) distributions were calculated. Joinpoint software and polynomial regression were used to assess trends over time. From 2013 through 2023, obesity prevalence increased among ACSMs, from 14.7% to 24.2%. Although obesity rates among civilians were consistently higher, this gap narrowed over the course of the decade. The same pattern was seen in young men (ages 17-24 years). Civilians have greater proportions within the highest classes of BMI than ACSMs. Persistently high obesity prevalence among ACSMs overall and in young men, particularly since 2019, may affect military recruitment, retention, and ultimately, strength and readiness.

What are the new findings?

From 2013 through 2023, the prevalence of obesity increased significantly among U.S. active component service members, 2019 to 2023 in particular, while prevalence among civilians remained consistently high. The pattern of obesity is especially relevant in young men, the largest source of potential and newly accessed military recruits.

What is the impact on readiness and force health protection?

The persistently high prevalence of obesity among civilians and growing prevalence of obesity among active component service members in general, and among young men in particular, may affect military recruitment, retention, and ultimately, strength and readiness.

Background

The U.S. Department of Defense (DOD) experienced agency-wide recruitment shortfalls in 2022 and 2023.¹ Excess body weight is a common disqualification for recruitment and retention of military members.² Some authors have suggested that the high prevalence of weight-ineligible young people has compromised national security by reducing recruitment.³ Obesity also places a substantial burden on the Military Health System (MHS).⁴

Reports have found that the prevalence of obesity in U.S. military members increased slightly during the COVID-19 pandemic,⁵ but prevalence of obesity in the overall U.S. civilian adult population remained level.⁶ Examining whether trends in obesity prevalence are similar, when sex and age standardized, for the active component military and civilian populations, as well as for young men from both populations, is ultimately relevant to U.S. military strength and readiness.

The objective of this study was to examine trends over the past decade in the prevalence of obesity among U.S. active component service members (ACSMs) and civilians ages 17-62 years, both overall and by sex, to understand whether trends in these populations were similar or different. This study highlights trends in young men ages 17-24 years among both populations, to examine differences in the prevalence of obesity between potential civilian and newly accessed military recruits. Finally, this study visualizes the cross-sectional distribution of body mass index (BMI) at the end of the study period, in both men and women, to compare the age-standardized distribution of BMI categories between military and civilian populations.

Methods

Data sources

For the ACSM population, this study employed a census of medical records with measured height and weight data from January 1, 2013 through December 31, 2023 from the MHS Data Repository (MDR). An encounter record in MDR can be initiated by individuals seeking care or by a healthy individuals completing an annual physical examination requirement. For each calendar year (e.g., 2013, 2014, etc.), the first encounter that included a non-pregnant height and weight measurement for an individual was abstracted from the MDR and linked to demographic data from the Defense Medical Surveillance System (DMSS).⁷ The same individual could be represented in multiple years of this study period, but never more than once every given year. Records with missing racial or ethnic group or sex data were excluded (n=271,679, 2.2%).

For civilians, this study utilized measured height and weight as well as demographic data from 4 survey cycles of the National Health and Nutrition Examination Survey (NHANES): 2013-2014, 2015-2016, 2017-March 2020, and August 2021-August 2023. NHANES is a cross-sectional, interview- and examination-based survey representative of the U.S. civilian, non-institutionalized population, approved by the National Center for Health Statistics (NCHS) Ethics Review Board.⁸ Non-pregnant NHANES participants ages 17-62 years (i.e., ACSM age range) with measured height and weight were included in this study.

Body mass index categories

BMI was calculated as weight in kilograms divided by height in meters squared, rounded to 1 decimal place. BMI categories were defined as underweight (BMI<18.5), normal weight (BMI 18.5<25.0), overweight (BMI 25.0<30.0), and obesity (BMI≥30.0). Obesity was further classified as class 1 obesity (BMI 30.0<35.0), class 2 obesity (BMI 35.0<40.0), and class 3 obesity (BMI≥40.0).⁹ Records from ACSMs with BMI less than or equal to 12 or greater than or equal to 50 were considered implausible and excluded from this study (n=6,562, 0.1%).

Statistical analysis

Analyses were conducted using R version 4.4.0 including survey package version 4.4-2 (R Foundation), SAS-Enterprise Guide version 8.3 (SAS Institute, Inc.), and Joinpoint Regression Program version 5.4.0 (National Cancer Institute). A 2-sided p-value of less than .05 was used to determine statistical significance.

Prevalence of obesity

The crude prevalence of obesity among ACSMs was calculated both overall and by sex, age, racial and ethnic group, and branch of military service, for each year, 2013–2023. Because ACSM data are a census of the population, confidence intervals (CIs) were not calculated. Overall, and for every demographic group, the percentage point change and relative percentage change over the study period were calculated using the prevalence of obesity in 2013 and 2023.

For civilians, examination survey weights were used to estimate the crude prevalence of obesity overall and by sex, age, and racial and ethnic group, for each survey cycle; Korn and Graubard CIs were calculated, and estimates were evaluated for reliability according to the NCHS Data Presentation Standards for Proportions.¹⁰ Percentage point change and relative percentage change were not calculated for civilians due to the unequal lengths and spacing of NHANES survey cycles.

Overall prevalence of obesity for ACSMs and civilians were also standardized to the sex and age structure of the ACSM study population in 2023 to account for demographic composition differences between and within these populations over time.

Trends in obesity

Statistical testing for trends in obesity over time were conducted by sex, age, racial and ethnic group, and branch of military service to provide subgroup information, which is relevant for military retention and recruitment, particularly for young men (ages 17-24 years).

For ACSMs, Joinpoint software (using default settings and weighted BIC model) was used to identify inflection points in obesity prevalence over time, and to test whether apparent changes in slope at inflection points were significant. The difference in slope of trends before and after significant inflection points, measured in annual percentage point change, were reported.

For civilians, quadratic and linear trends in obesity prevalence over time were examined in regression models with the survey cycle modeled as an orthogonal polynomial, accounting for the unequal spacings and lengths of NHANES survey cycles, using the NCHS Guidelines for Analysis of Trends.¹¹ Because only 4 NHANES survey cycles were included in this study, Joinpoint software was not used to analyze civilian trends.

Distributions of body mass index

The prevalence of each BMI-defined weight category was calculated and used to visualize the 2023 distributions of BMI by sex among ACSMs in 2023 and the civilian population from August 2021 through August 2023, standardized to the age structure of the ACSM study population in 2023.

Results

Demographics of active component service members and civilians

This study included a cumulative total of 12,262,745 ACSM records of measured height and weight from the MHS Data Repository from 2013 through 2023 (Table 1). The demographic distribution of this study’s ACSM population is similar to active duty members in the DOD 2023 Demographics Report.¹²

This study included a cumulative total of 19,334 civilian participants from 4 survey cycles of NHANES (Table 1). NHANES estimates are representative of the U.S. non-institutional, civilian population.¹³

The population of ACSMs is younger (78.1% ages 17-34 years), with a higher percentage of men (82.9%) than the U.S. civilian population (39.3% ages 17-34 years, 50.0% men).

Obesity trends overall

Sex- and age-standardized prevalence of obesity in ACSMs increased from 14.7% in 2013 to 18.7% in 2020; from the joinpoint at 2020, obesity prevalence rose more rapidly, to 24.2% in 2023 (difference in slope before and after joinpoint 1.33, p<0.001) (Table 2). The standardized estimated prevalence of obesity among civilians, which was consistently higher than ACSMs throughout this period, increased from 31.3% (95% CI 29.2, 33.6) in the NHANES 2013-2014 survey cycle to 37.8% (95% CI 34.7, 40.9) 2017–March 2020 and then declined to 33.0% (95% CI 30.1, 36.0) August 2021–August 2023 (quadratic trend p=0.04, linear trend p=0.49) (Table 3).

Trends in male and female obesity

From 2013 through 2023, crude prevalence of obesity, in both men and women, was lower among ACSMs than civilians, although the difference narrowed over time (Figure 1). Prevalence of obesity in male ACSMs increased from 15.7% in 2013 to 18.1% in 2019; from the joinpoint at 2019 obesity increased more rapidly, to 25.3% in 2023 (difference in slope before and after joinpoint 1.42, p<0.001). Obesity increased in female ACSMs from 8.3% in 2013 to 12.0% in 2019; from the joinpoint at 2019 obesity increased more rapidly, to 19.6% in 2023 (difference in slope before and after joinpoint 1.38, p<0.001).

Estimated prevalence of obesity in male civilians increased from 33.5% (95% CI 30.1, 37.0) in 2013-2014 to 41.4% (95% CI 36.7, 46.3) during 2017–March 2020, then declined to 38.6% (95% CI 34.7, 42.7) during August 2021–August 2023 (quadratic trend p=0.04, linear trend p=0.05). In female civilians, obesity remained consistent from 2013-2014 (40.9%; 95% CI 37.7, 44.1) to August 2021–August 2023 (41.1%; 95% CI 35.7, 46.6) (quadratic trend p=0.67, linear trend p=0.85).

Trends in young male obesity

Among young male (ages 17-24 years) ACSMs, crude obesity prevalence increased from 7.9% in 2013 to 9.9% in 2019; from the joinpoint at 2019, obesity increased more rapidly to 15.1% in 2023 (difference in slope before and after joinpoint 0.98, p<0.001) (Figure 2).

Among young male civilians, estimated prevalence of obesity did not change significantly, from 21.1% (95% CI 15.3, 28.0) in 2013-2014 to 24.5% (95% CI 19.2, 30.6) during August 2021–August 2023 (quadratic trend p=0.08, linear trend p=0.35).

Distributions of body mass index

Age-standardized distributions of BMI according to sex, among ACSMs in 2023 and civilians during August 2021–August 2023, were visibly different (Figure 3). Male ACSMs demonstrated lower proportions in the highest classes of obesity (class 2 obesity 4.0%, class 3 obesity 0.7%) in comparison to the civilian male population (class 2 obesity 8.2%; 95% CI 6.5, 10.2 and class 3 obesity 5.7%; 95% CI 4.5, 7.1). This pattern was even more striking in women: Female ACSMs demonstrated even smaller proportions in the highest classes of obesity (class 2 obesity 3.6%, class 3 obesity 0.8%) when compared to women in the civilian population (class 2 obesity 9.0%; 95% CI 6.9, 11.5 and class 3 obesity 11.3%; 95% CI 9.7, 13.1).

Discussion

This study included newer data, collected after the COVID-19 pandemic, to describe trends in sex- and age-standardized prevalence of obesity over the past decade among ACSMs and civilians aged 17-62 years, as well as young men.

From 2013 through 2023, the prevalence of obesity in male and female ACSMs increased, while standardized estimated prevalence among civilians ages 17-62 years increased slightly but ended similar to the start of the decade. The difference in obesity prevalence between the populations apparently narrowed. Interestingly, a majority of the increase in ACSM obesity prevalence occurred recently, from 2019 until 2023. The pattern of increasing ACSM obesity prevalence and consistently high prevalence in civilians was also present in young men (ages 17-24 years), the largest source of potential military recruits as well as newly accessed military members. More than 1 in 5 young male civilians had obesity throughout the 10-year study period.

The growing prevalence of obesity among ACSMs overall and in young men, particularly since 2019, could lead to poorer retention of newly accessed recruits and an increased burden on the MHS. The persistently high obesity prevalence among civilians presumably reduces the pool of height- and weight-eligible potential military recruits, although other factors, such as education and medical conditions,¹⁴ are considered for U.S. military accession.

Force-wide changes within the DOD may explain the significantly greater 2019–2023 increase in obesity among ACSMs. In early 2020, Force Health Protection Guidance was published in response to the COVID-19 pandemic, limiting close contact and reducing workplace access, leading to suspended physical fitness testing requirements by the service branches.¹⁵ This period also saw the resolution of the War on Terror and withdrawal of troops from Iraq and Afghanistan in 2021, changing the military from a wartime to peacetime posture.¹⁶ These changes may have shifted emphasis from combat to non-combat occupations and reduced demand for exceptional physical capabilities.

This study has several strengths. Data collected from MDR and linked to DMSS provide a near census of ACSMs, due to the annual physical examination requirement. This study population closely matched the DOD 2023 Demographics Report.¹² NHANES data are nationally representative of the civilian, non-institutional population and do not rely on survey participants seeking health care.¹³ We used measured height and weight from both data sources, which is more accurate than relying on self-reported height and weight.¹⁷

This study has several limitations. Collection and interpretation of the data sources differed. DMSS provides a nearly complete, continuous census of ACSMs in MDR, while NHANES is a cross-sectional survey with a sample selected through a complex, multi-stage probability design. Statistical power to detect significant civilian trends was lower than for ACSMs due to the smaller NHANES sample size. Data from the upcoming Military Health and Nutrition Examination Study (MHANES) may be more directly comparable to NHANES.¹⁸ Furthermore, the first non-pregnant record of height and weight from MDR was used for ACSMs, biasing data selection from earlier in the calendar year, whereas NHANES data are collected throughout a calendar year. Seasonal variations in body weight may occur, although the magnitude is likely small.¹⁹ Additionally, it could not be ascertained whether ACSMs had obesity before joining the military or if they developed obesity after accession.

Another important consideration when interpreting the results of this study are the limitations of using BMI to define obesity. While BMI is simple, inexpensive, and widely accepted for obesity surveillance, it does not distinguish body fat from lean body mass, nor describes body fat distribution within an individual.²⁰ When comparing BMI distributions, it is apparent that a higher proportion of ACSMs than civilians are in the overweight and class 1 obesity categories; conversely, a higher proportion of civilians have class 2 and class 3 obesity (i.e., severe obesity). Some ACSM classifications of overweight or class 1 obesity are likely partially attributable to higher levels of fitness and lean muscle mass in ACSMs than in civilians. Body composition measurement has recently come under increased scrutiny and will be included in a rapid review of military standards.²¹ Other measures of adiposity that are better proxies for central adiposity, such as waist circumference and body composition scans, may reduce some limitations of using height and weight alone to define obesity.

Future studies could compare service-specific height and weight military accession standards with the findings from this study, to ultimately inform potential effects on military strength and readiness, as well as the burden of obesity on the MHS.

Author Affiliations

Epidemic Intelligence Service, U.S. Centers for Disease Control and Prevention, Atlanta, GA: MAJ Emmerich; National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, MD: MAJ Emmerich, Dr. Stierman, Dr. Ogden; Epidemiology and Analysis Branch, Armed Forces Health Surveillance Division, Public Health Directorate, Defense Health Agency, Silver Spring, MD: Dr. Mabila

Disclaimer

The findings and conclusions in this article are those of the authors and do not represent official position of the National Center for Health Statistics, U.S. Centers for Disease Control and Prevention.

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Perinatal mental health conditions among U.S. active component service women, 2016–2022

Mon, 01 Dec 2025 00:00:00 Z

Abstract

Although mental health conditions are the leading underlying cause of maternal mortality, there is limited research on the prevalence of perinatal mental health conditions among active duty service women (ADSW). In this study of live-born deliveries among U.S. ADSW (n=62,729) with pregnancy start and end dates (i.e., dates of last menstrual period and infant delivery, respectively) from October 1, 2016 through December 31, 2021, International Classification of Diseases, 10th Revision, Clinical Modification diagnosis codes were used to identify mental health conditions: trauma and stressor-related disorders, anxiety and panic disorders, depressive disorders, suicidal ideation or attempt, and eating disorders. Data were collected through 1 year postpartum, until December 31, 2022. The prevalence of diagnosed mental health conditions from 1 year prior to pregnancy through 1 year postpartum was 33.8%. Trauma and stressor-related disorders were most prevalent (23.1%), followed by anxiety and panic disorders (16.9%), depressive disorders (14.6%), suicidal ideation or attempt (1.6%), and eating disorders (0.4%). The prevalence of mental health conditions was higher in the postpartum period (22.0%) compared to pregnancy (18.4%) and prior to pregnancy (15.0%). Overall, higher prevalence of these conditions was found among non-Hispanic Black ADSW (37.4%), and those who were unmarried (38.4%), never deployed (34.9%), or in the Army (37.4%) and Navy (36.4%).

What are the new findings?

One in 3 active duty service women were diagnosed with a mental health condition in the year preceding pregnancy through 1 year postpartum. Overall, non-Hispanic Black and junior enlisted active duty service women demonstrated higher prevalences of mental health conditions compared to all other racial and ethnic groups and military ranks.

What is the impact on readiness and force health protection?

Mental health issues can lead to early returns from deployment, which can adversely affect unit missions and cohesion. Service member retention is linked to mental health, with those who experience mental health conditions less likely to remain in military service. As the proportion of women serving in the military continues to increase, targeted perinatal mental health support and interventions should be prioritized to improve active duty service women's psychological well-being and maintain force readiness.

Background

Most (93.5%) U.S. active duty service women (ADSW) are of childbearing age (18-44 years), averaging 15,000 live births per year.¹ From 2017 through 2019, 22.7% of maternal mortality in the general U.S. population was attributable to mental health conditions, including deaths due to suicide or overdose.² While comparable maternal mortality data are not published for ADSW, during the same period 37.8% of ADSW received a mental health diagnosis during pregnancy or through 1 year postpartum.³

Recent research suggests that deaths from suicide or accidental overdose account for a much larger percentage of pregnancy-associated deaths among ADSW (39.4%) compared to civilian women (8.8–10.9%).⁴ The increased burden of mental health conditions among ADSW continues after military service, with as many as 46.7% of female veterans reporting perinatal depression, compared to 10% of civilian women.⁵ Existing research only provides the prevalence of any mental health condition versus specific diagnoses, without estimates for sub-populations of ADSW. This report describes the 2016–2022 prevalence of perinatal mental health conditions among ADSW, with data presented for 5 diagnostic categories: trauma and stressor-related disorders, anxiety and panic disorders, depressive disorders, suicidal ideation or attempt, and eating disorders.

Methods

Data sources

This study utilized data from the Department of Defense (DOD) Birth and Infant Health Research (BIHR) program, a population-level surveillance and research database that identifies live births among Military Health System (MHS) beneficiaries. Detailed information on BIHR data and methodologies have been described elsewhere.^6,7 BIHR includes military personnel data from the Defense Manpower Data Center (DMDC) and administrative medical encounter data from the MHS Data Repository; BIHR data are used to identify and link live births to birth mothers and military sponsors through the Defense Enrollment Eligibility Reporting System, to describe associated demographic and medical characteristics. These data are linked using the unique 10-digit identifiers (i.e., Electronic Data Interchange Personal Identifier) assigned to each person with a direct DOD relationship. Institutional Review Board approval (NHRC.1999.0003) for this study was obtained from the Naval Health Research Center, with informed consent waived in accordance with criteria set forth by 32 Code of Federal Regulations Section 219.116(d).

Study population

The source population for this study included all live-born deliveries among ADSW captured in BIHR data with pregnancy start and end dates (i.e., dates of last menstrual period, or LMP, and delivery, respectively) from October 1, 2016 through December 31, 2021. This timeframe was selected to include medical data that were captured exclusively after the transition to the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM), which occurred on October 1, 2015. Deliveries were excluded if an ADSW did not have a record of TRICARE enrollment or any medical encounter data for at least 10 of 12 months during both the year preceding pregnancy and year following delivery.

Mental health conditions

Mental health conditions of interest were identified using ICD-10-CM codes and then grouped into 5 categories: trauma and stressor-related disorders (F43.x), anxiety and panic disorders (F40.x, F41.x), depressive disorders (F32.x, F33.x, F34.x), suicidal ideation or attempt (R45.851, T14.91), and eating disorders (F50.x), in accordance with the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision.⁸ Conditions were measured within 3 timeframes: pre-pregnancy (year prior to LMP), pregnancy (from LMP to date of delivery), and postpartum (year following date of delivery). For each diagnostic category and timeframe, cases were identified by the presence of diagnosis codes on 1 inpatient or 2 outpatient records on separate dates. This method was selected to improve reliability for capturing true mental health diagnoses and not exclusion or ‘rule out’ diagnoses, which are common with new mental health conditions, as many conditions exhibit overlapping symptoms. Diagnostic categories and timeframes were not mutually exclusive, meaning that ADSW with live-born deliveries could be identified with multiple mental health conditions within multiple mental health diagnostic categories at multiple timeframes in the study period. For example, if an ADSW had both an anxiety and depressive disorder diagnosis she would be represented individually in both diagnostic categories (anxiety or panic disorders and depressive disorders).

To provide the prevalence of diagnosed mental health conditions pre-pregnancy through 1 year postpartum, an overall composite variable was created to identify deliveries that met criteria for any mental health condition of interest during any timeframe. Variables were created to identify deliveries with any diagnosed mental health conditions of interest within each timeframe (pre-pregnancy, pregnancy, postpartum). To evaluate the prevalence of specific mental health conditions, variables were created for each diagnostic category (trauma/stress, anxiety/panic, depressive, suicidal ideation/attempt, eating disorders) assessed over the entire study period and within each timeframe (pre-pregnancy, pregnancy, postpartum). We also created a co-morbid mental health condition variable that summed the number of diagnosed mental health conditions (from the 5 diagnostic categories of interest) for each individual throughout the study period (1 year pre-pregnancy through 1 year postpartum). The count ranged 0–5 and was categorized as 0, 1, 2, or 3+.

Covariates

Demographic and military factors were obtained from DMDC files corresponding to the month of delivery. Variables included racial or ethnic group (i.e., American Indian or Alaska Native, Asian, Hispanic, multiracial, Native Hawaiian/Pacific Islander, non-Hispanic Black, non-Hispanic White, unknown), age at infant delivery (<20, 20-24, 25-29, 30-34, 35+ years), marital status (married, unmarried/unknown), military rank and pay grade (junior enlisted [E1-E4], mid-/senior enlisted [E5-E9], officer/warrant officer [O1-O10/W01-W05]), branch of service (Army, Navy, Air Force, Marine Corps, Coast Guard), and deployment history prior to infant delivery (ever deployed, never deployed). Deployment history was limited to deployments in support of post-September 11, 2001 (9/11) operations, predominately in or near the Middle East.

Statistical analysis

Frequencies and percentages were used to describe the prevalence of mental health conditions during the study period, and by demographic and military characteristics. Confidence intervals (CIs) were also calculated to assess differences between subgroups. Prevalence was not calculated for subgroups with less than 30 cases. Prevalence was calculated for the mental health conditions overall and by specific diagnostic category; measures were calculated throughout the entire study (1 year pre-pregnancy through 1 year postpartum) and by specific timeframe. All data management and statistical analyses were performed using SAS, Version 9.4 (SAS Institute Inc., Cary, NC).

Results

Analytic population

The source population included 62,729 live-born deliveries among 54,471 unique ADSW. After excluding deliveries among ADSW with less than 10 of 12 months of either TRICARE enrollment or medical encounter data before and after pregnancy, the final analytic cohort comprised 56,371 deliveries among 49,262 unique ADSW (89.9% of source population). Excluded deliveries were more likely to be among ADSW younger than age 20 years, of junior enlisted rank, and in the Marine Corps.

Prevalence of any mental health condition

Overall, 33.8% of deliveries were among ADSW diagnosed with at least 1 mental health condition of interest at any time during the study period (Table 1). Deliveries to non-Hispanic Black ADSW had the highest prevalence of any mental health condition (37.4%; 95% CI 36.6, 38.2) compared to all other racial and ethnic groups (range 23.6–34.3%). A higher prevalence of mental health conditions was found among deliveries to unmarried versus married ADSW (38.4%; 95% CI 37.5, 39.2 vs. 32.5%; 95% CI 32.1, 33.0). The prevalence of mental health conditions was lower among deliveries to officers (20.8%; 95% CI 20.1, 21.6) compared to those among junior enlisted (38.5%; 95% CI 37.3, 39.6) and mid- or senior enlisted ADSW (36.6%; 95% CI 36.1, 37.0).

ADSW in the Army had the highest prevalence of mental health conditions (37.4%; 95% CI 36.7, 38.1), followed by those in the Navy (36.4%; 95% CI 35.7, 37.2), compared to deliveries among ADSW in the Air Force, Coast Guard, and Marine Corps (range 22.7–31.0%). Those who had never deployed had a higher prevalence of mental health conditions compared to those who had a history of deployment (34.9%; 95% CI 34.4, 35.3 vs. 31.9%; 95% CI 31.2, 32.5), where the definition of deployment was limited to support of post-9/11 operations.

The prevalence of any diagnosed mental health condition increased over time during the perinatal period, from 15.0% (95% CI 14.7, 15.3) in the year prior to pregnancy to 18.4% (95% CI 18.1, 18.7) during pregnancy to 22.0% (95% CI 21.7, 22.4) in the year following pregnancy. Throughout the study cohort, 17.9% (95% CI 17.6, 18.2) of deliveries were to ADSW with 1 diagnosed mental health condition, 10.0% (95% CI 9.7, 10.2) were to ADSW with 2 mental health conditions, and 6.0% (95% CI 5.8, 6.2) were to ADSW with 3 or more mental health conditions. Of those diagnosed with any of the 5 mental health conditions during the study period, 29.4% had at least 2 diagnoses, and 17.7% had 3 or more diagnoses (data not shown).

Prevalence of specific mental health conditions

Throughout the entire study period, the most commonly diagnosed mental health conditions were trauma and stressor-related disorders (23.1%; 95% CI 22.8, 23.5), followed by anxiety and panic disorders (16.9%; 95% CI 16.6, 17.3), depressive disorders (14.6%; 95% CI 14.4, 14.9), suicidal ideation or attempt (1.6%; 95% CI 1.5, 1.7), and eating disorders (0.4%; 95% CI 0.3, 0.4) (Table 2). Similar to the overall prevalence of mental health conditions, when examined by specific diagnostic category, a higher prevalence of all diagnoses was found in deliveries of ADSW who were unmarried, of enlisted rank, in the Army or Navy, or who had never deployed.

For trauma and stressor-related disorders, deliveries to non-Hispanic Black ADSW had the highest prevalence (27.5%; 95% CI 26.7, 28.2) compared to all other racial and ethnic groups (range 17.2–22.8%). By age, the lowest prevalence for trauma and stress-related disorders was in deliveries among ADSW ages 30-34 years (18.5%; 95% CI 17.9, 19.1) compared to all other age groups (range 20.9–26.8%). The highest prevalence of trauma and stressor-related disorders was seen postpartum (14.2%; 95% CI 13.9, 14.5), compared to pre-pregnancy (10.3%; 95% CI 10.1, 10.6) and during pregnancy (9.4%; 95% CI 9.1, 9.6).

For anxiety and panic disorders, the lowest prevalence was found among deliveries to Native Hawaiian or Pacific Islander (8.1%; 95% CI 6.2, 10.0) and non-Hispanic Asian (11.1%; 95% CI 9.8, 12.4) ADSW compared to all other racial or ethnic groups (range 15.8–18.7%). Deliveries to ADSW in the Navy had the highest prevalence (19.2%; 95% CI 16.8, 19.9) compared to all other service branches (range 13.1–17.0%).

For depressive disorders, higher prevalence was found among deliveries to junior enlisted (17.4%; 95% CI 16.5, 18.3) and mid- or senior enlisted ADSW (16.2%; 95% CI 15.8, 16.5) compared to officers (7.3%; 95% CI 6.8, 7.8). The lowest prevalence of depressive disorders was seen pre-pregnancy (4.6%; 95% CI 4.5, 4.8) compared to during pregnancy (8.3%; 95% CI 8.1, 8.6) and postpartum (7.8%; 95% CI 7.6, 8.1).

For suicidal ideation or attempt, junior enlisted ADSW prevalence (3.4%; 95% CI 3.0, 3.8) was 8.5 times the prevalence among officers (0.4%; 95% CI 0.3, 0.5) and 2 times prevalence in mid- and senior enlisted ADSW (1.6%; 95% CI 1.4, 1.7).

For eating disorders, there were no significant differences in prevalence by demographic or military characteristics as well as timeframe.

Discussion

In this study of live-born deliveries among ADSW, 1 in 3 were diagnosed with a mental health condition 1 year prior to pregnancy through 1 year postpartum. Of those diagnosed with a mental health condition, 1 in 4 were diagnosed with a trauma and stressor-related disorder, which existing research has linked to an increase in suicide risk, particularly among women.^9-12 Mental health conditions are also associated with adverse pregnancy outcomes, such as pre-term birth and hypertensive disorders of pregnancy, with highest risk in those with trauma or stressor-related disorders.^13-16 This high prevalence (33.8%) of mental health conditions reveals the potential risk of adverse pregnancy outcomes among ADSW.^14,16,17 To our knowledge, this is the largest study to examine the prevalence of specific mental health conditions before and during the perinatal period among a sample of live births to ADSW.³

There is limited research focused on perinatal mental health conditions among ADSW. Abramovitz and colleagues investigated the prevalence of post-traumatic stress disorder (PTSD) (identified by diagnosis codes) among 134,244 pregnant ADSW from 2007 through 2014, utilizing the same data source (BIHR) as the current study. Abramovitz et al. found that 1.7% of ADSW had a diagnosis of PTSD from the year prior to pregnancy through the end of pregnancy.¹⁸ In contrast, this study estimated the prevalence of all trauma or stressor-related disorders, not just PTSD, and found a higher prevalence during pre-pregnancy (10.3%) and pregnancy (9.4%). A recent study of a nationally representative sample in the U.S. found a prevalence of a trauma or stressor-related disorder during pregnancy of only 0.2%, much lower than reported in this study and existing studies of military populations.¹⁴

Andriotti and colleagues utilized TRICARE claims data to identify new mental health cases in the 2 years prior to pregnancy, during pregnancy, and 2 years postpartum.¹⁷ Andriotti et al. provided limited details, however, for which mental health conditions were included in their study or which specific diagnosis codes were used to identify mental health cases. As in our study, Andriotti et al. found an increase in the prevalence of mental health conditions in the postpartum period (20%) compared to pregnancy (15%).¹⁷ Globally, the prevalence of perinatal mental health conditions is estimated to be 10% during pregnancy and 13% postpartum, which is lower than that found by Andriotti and colleagues¹⁷ as well as the current study of ADSW.¹⁹

A U.S. Government Accountability Office (GAO) report of perinatal mental health conditions among TRICARE beneficiaries, 2017–2019, found that 37.8% of ADSW had a diagnosed mental health condition during pregnancy or in the year postpartum.³ The GAO estimate is higher than this study’s estimated 33.8% prevalence, with several methodological differences between the 2 studies. First, the GAO report defined mental health cases by the presence of any mental health ICD-10 code (F01-F99) and only required 1 code, either inpatient or outpatient. The current study limited analysis to 5 categories of mental health conditions defined by the presence of either 1 inpatient ICD-10 code or 2 outpatient ICD-10 codes on separate days. We chose this method to improve reliability of capturing a true diagnosed case versus exclusion or ‘rule out’ diagnoses. Second, the GAO report only included mental health conditions diagnosed during pregnancy through 1 year postpartum, while this study also included mental health diagnoses in the year prior to pregnancy. Finally, this study only included live-born deliveries, while the GAO report included pregnancy losses and stillbirths. Despite these methodological differences, the results from the GAO report and this study are similar: Both found a higher prevalence of mental health conditions in non-Hispanic Black ADSW compared to other racial and ethnic groups, and a higher prevalence among ADSW in the Army and Navy compared to other service branches.

One key difference between the GAO report and this study is that the GAO found a higher prevalence of mental health conditions among ADSW who deployed, while this study found that ADSW who had not deployed had a higher prevalence. To capture deployment history, the GAO report relied on ICD-10 code (Z91.82), while this study obtained deployment data from DMDC limited to deployments in support of post-9/11 operations. This difference in methodology may explain the differing results.

This study also found lower prevalence among Native Hawaiian and Pacific Islander ADSW compared to all other racial and ethnic groups, which conflicts with existing, albeit limited, research.^20,21 This study’s population included 1,419 ADSW who identified as American Indian, Alaska Native, Native Hawaiian, or Pacific Islander, which provided a rare opportunity to evaluate perinatal mental health in these historically under-researched populations. Women of those racial and ethnic groups may face unique barriers to care due to living in remote geographic locations, lack of culturally appropriate screening tools, insufficient cultural congruency with health care providers, and other structural factors that increase their risk of poor health outcomes.²⁰ Those risks may be mitigated by military service, which provides access to health care and stable salaries, both factors that may help explain why rates of perinatal mental health conditions in this study were lower among Native Hawaiian and Pacific Islander ADSW compared to other racial and ethnic groups, including American Indian and Alaska Native service women.

Strengths of this study include the use of a large, population-based dataset of ADSW. All women in this study were employed, with access to health care, which provided a unique opportunity to examine differences in perinatal mental health by socio-demographic characteristics. Another strength of this study is that mental health conditions were evaluated at 3 distinct points in time—from 1 year prior to pregnancy, during pregnancy, and at 1 year postpartum—which allowed assessment of prevalence over time. Lastly, only live-born deliveries were included in this study, in recognition of the singular impact that experiencing a pregnancy loss or stillbirth may have on mental health.

Limitations of this study include the use of medical encounter data, which may be subject to coding accuracy and quality. The ICD-10-CM diagnosis codes utilized to identify mental health conditions have not been validated, but we attempted to improve accuracy of capture through our requirement of 1 inpatient or 2 outpatient diagnoses on separate days. The study observation period (2016–2022) included the COVID-19 pandemic, which may have had impacts on the prevalence and detection of perinatal mental health conditions.^22,23

Additionally, the prevalence of mental health conditions only reflects those actively seeking care or otherwise engaged in the health care system. Many service members may not seek health care due to stigma, despite access to these resources.^24-26 A recent GAO report²⁷ found that only 52% of U.S. service women who delivered at a military hospital or clinic received recommended perinatal mental health screenings, increasing risk of under-diagnosis.

The true prevalence of mental health conditions among ADSW before and during the perinatal period is likely much larger than reported in this study. Future research should include prospective screening studies to identify ADSW who are not seeking care for mental health but who may meet diagnostic criteria for a mental health diagnosis. Lastly, these findings are not completely generalizable to all ADSW because those excluded were more likely of younger ages and junior enlisted members, resulting in a study population biased towards slightly older ADSW with more time in service.

This study highlights the prevalence of perinatal mental health conditions among military sub-populations. ADSW have unique mental health and reproductive health needs as a result of stressors inherent to military life, including, but not limited to, potential (and sometimes sudden) deployment and engagement in armed conflict.^28,29

Mental health directly affects physical health. Military service members who are mentally fit are more likely to perform their duties efficiently, enhancing operational readiness. Mental health issues can lead to early returns from deployment, which can affect unit mission and cohesion. Ten percent of all aeromedical evacuations during operations Enduring Freedom, Iraqi Freedom, and New Dawn were due to psychiatric reasons.³⁰ Service member retention is also linked to mental health, with those experiencing mental health conditions less likely to remain in the military than those not experiencing mental health conditions.³¹

Enhanced screening and targeted management of mental health conditions may be a mechanism to improve service member retention and decrease adverse pregnancy outcomes among this population. Future research should employ qualitative methods to further explain differences in prevalence by demographic factors. Prospective studies are needed to evaluate effective screening practices and interventions for perinatal mental health conditions among ADSW.

Author Affiliations

Womack Army Medical Center, Ft Bragg, NC: MAJ Manzo; Yale School of Nursing, West Haven, CT: MAJ Manzo, Dr. Combellick, Dr. Womack; Leidos, Inc., San Diego, CA: Dr. Hall; Veterans Administration Connecticut Healthcare System, West Haven, CT: Dr. Combellick, Dr. Harpaz-Rotem, Dr. Womack; Yale University, New Haven, CT: Dr. Harpaz-Rotem; Air Force Medical Command, Falls Church, VA: Lt Col Phillips

Disclaimer

MAJ Manzo and Lt Col Phillips are military service members. This work was prepared as part of official duties. Title 17, U.S.C. Section 105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S.C. Section 101 defines a U.S. Government work as work prepared by a military service member or employee of the U.S. Government as part of official duties. Report 25-16 was supported by the U.S. Navy Bureau of Medicine and Surgery under work unit 60504.

The views expressed in this article are those of the authors and do not reflect official policy nor position of the departments of the Army or Navy, Department of Defense, nor the U.S. Government. The study protocol was approved by the Naval Health Research Center Institutional Review Board in compliance with all applicable federal regulations governing human subject protection. Research data were derived from approved Naval Health Research Center Institutional Review Board protocol NHRC.1999.0003.

Acknowledgments

The authors are grateful to Ava Marie S. Conlin, DO, MPH, principal investigator of the Department of Defense Birth and Infant Health Research (BIHR) program at the Naval Health Research Center, who facilitated access to BIHR data and provided valuable feedback throughout the study design and execution; and to Celeste Romano, MS, epidemiologist with the BIHR program, who generously agreed to review the manuscript and provided valuable feedback.

References

U.S. Centers for Disease Control and Prevention. Women’s Reproductive Health, May 15, 2024. U.S. Dept. of Health and Human Services. Accessed Sep. 21, 2024. https://www.cdc.gov/reproductive-health/women-health/?cdc_aaref_val=https://www.cdc.gov/reproductivehealth/womensrh/index.htm
U.S. Dept. of Health and Human Services. Pregnancy-Related Deaths: Data from Maternal Mortality Review Committees in 36 US States, 2017-2019. Accessed Oct. 2, 2024. https://www.hrsa.gov/sites/default/files/hrsa/advisory-committees/infant-mortality/meetings/busacker-maternalmortality.pdf
U.S. Government Accountability Office. Report to Congressional Committees: Defense Health Care–Prevalence of and Efforts to Screen and Treat Mental Health Conditions in Prenatal and Postpartum TRICARE Beneficiaries. GAO-22-105136. May 2022. Accessed Sep. 23, 2023. https://www.gao.gov/assets/gao-22-105136.pdf
Romano CJ, Hall C, Bukowinski AT, Gumbs GR, Conlin AMS. Pregnancy-associated and pregnancy-related deaths in the United States military, 2003-2014. Am J Obstet Gynecol. 2022;227(3):508.e1-508.e9. doi:10.1016/j.ajog.2022.04.020
Smythe KL, Petersen I, Schartau P. Prevalence of perinatal depression and anxiety in both parents: a systematic review and meta-analysis. JAMA Network Open. 2022;5(6):e2218969-e2218969. doi:10.1001/jamanetworkopen.2022.18969
Bukowinski AT, Conlin AMS, Gumbs GR, et al. Department of Defense Birth and Infant Health Registry: select reproductive health outcomes, 2003-2014. MSMR. 2017;24(11):39-49. Accessed Oct. 2, 2025. https://www.health.mil/reference-center/reports/2017/01/01/medical-surveillance-monthly-report-volume-24-number-11
Khodr ZG, Bukowinski AT, Hall C, et al. The Department of Defense Birth and Infant Health Research Program: assessing the reproductive health of U.S. active-duty women. Semin Reprod Med. 2018;36(6):351-360. doi:10.1055/s-0039-1678751
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision. American Psychiatric Association;2022.
Akbar R, Arya V, Conroy E, Wilcox HC, Page A. Posttraumatic stress disorder and risk of suicidal behavior: a systematic review and meta-analysis. Suicide Life Threat Behav. 2023;53(1):163-184. doi:10.1111/sltb.12931
Fox V, Dalman C, Dal H, et al. Suicide risk in people with post-traumatic stress disorder: a cohort study of 3.1 million people in Sweden. J Affect Disord. 2021;279:609-616. doi:10.1016/j.jad.2020.10.009
Pompili M, Sher L, Serafini G, et al. Posttraumatic stress disorder and suicide risk among veterans: a literature review. J Nerv Ment Dis. 2013;201(9):802-812. doi:10.1097/nmd.0b013e3182a21458
Ramsawh HJ, Fullerton CS, Mash HB, et al. Risk for suicidal behaviors associated with PTSD, depression, and their comorbidity in the U.S. Army. J Affect Disord. 2014;161:116-22. doi:10.1016/j.jad.2014.03.016
Accortt E, Mirocha J, Jackman S, et al. Association between diagnosed perinatal mood and anxiety disorders and adverse perinatal outcomes. J Matern Fetal Neonatal Med. 2021;35(25):9066-9070. doi:10.1080/14767058.2021.2014450
Brown CC, Adams CE, George KE, Moore JE. Mental health conditions increase severe maternal morbidity by 50 percent and cost $102 million yearly n the United States. Health Aff. 2021;40(10):1575-1584. doi:10.1377/hlthaff.2021.00759
Ding XX, Wu YL, Xu SJ, et al. Maternal anxiety during pregnancy and adverse birth outcomes: a systematic review and meta-analysis of prospective cohort studies. J Affect Disord. 2014;159:103-10. doi:10.1016/j.jad.2014.02.027
Logue TC, Wen T, Monk C, et al. Trends in and complications associated with mental health condition diagnoses during delivery hospitalizations. Am J Obstet Gynecol. 2022;226(3):405.e1-405.e16. doi:10.1016/j.ajog.2021.09.021
Andriotti T, Ranjit A, Hamlin L, et al. Psychiatric conditions during pregnancy and postpartum in a universally insured American population. Mil Med. 2022;187(7-8):e795-e801. doi:10.1093/milmed/usab154
Abramovitz LM, Lutgendorf MA, Bukowinski AT, et al. Posttraumatic stress disorder in a cohort of pregnant active duty U.S. military servicewomen. J Trauma Stress. 2021;34(3):586-595. doi:10.1002/jts.22656
Gruszczyńska-Sińczak I, Wachowska K, Bliźniewska-Kowalska K, Gałecki P. Psychiatric treatment in pregnancy: a narrative review. J Clin Med. 2023;12(14):4746. doi:10.3390/jcm12144746
Owais S, Faltyn M, Johnson AVD, et al. The perinatal mental health of Indigenous women: a systematic review and meta-analysis. Can J Psychiatry. 2020;65(3):149-163. doi:10.1177/0706743719877029
Kisely S, Alichniewicz KK, Black EB, et al. The prevalence of depression and anxiety disorders in indigenous people of the Americas: a systematic review and meta-analysis. J Psychiatr Res. 2017;84:137-152. doi:10.1016/j.jpsychires.2016.09.032
Chmielewska B, Barratt I, Townsend R, et al. Effects of the COVID-19 pandemic on maternal and perinatal outcomes: a systematic review and metaanalysis. Lancet Glob Health. 2021;9(6):e759-e772. doi:10.1016/s2214-109x(21)00079-6
Zanardo V, Manghina V, Giliberti L, et al. Psychological impact of COVID-19 quarantine measures in northeastern Italy on mothers in the immediate postpartum period. Int J Gynaecol Obstet. 2020;150(2):184-188. doi:10.1002/ijgo.13249
Chu KM, Garcia SMS, Koka H, Wynn GH, Kao TC. Mental health care utilization and stigma in the military: comparison of Asian Americans to other racial groups. Ethn Health. 2021;26(2):235-250. doi:10.1080/13557858.2018.1494823
Ben-Zeev D, Corrigan PW, Britt TW, Langford L. Stigma of mental illness and service use in the military. J Ment Health. 2012;21(3):264-273. doi:10.3109/09638237.2011.621468
Sharp ML, Fear NT, Rona RJ, et al. Stigma as a barrier to seeking health care among military personnel with mental health problems. Epidemiol Rev. 2015;37:144-162. doi:10.1093/epirev/mxu012
U.S. Government Accountability Office. Report to the Committee on Armed Services, House of Representatives: Defense Health Care–DOD Should Monitor Mental Health Screenings for Prenatal and Postpartum TRICARE Beneficiaries. GAO-25-107163. Apr. 2025. Accessed Sep. 15, 2025. https://www.gao.gov/assets/gao-25-107163.pdf
Gawron LM, Mohanty AF, Kaiser JE, Gundlapalli AV. Impact of deployment on reproductive health in U.S. active-duty servicewomen and veterans. Semin Reprod Med. 2018;36:361-370. doi:10.1055/s-0039-1678749
Manzo LL, Dindinger RA, Batten J, Combellick JL, Basile-Ibrahim B. The impact of military trauma exposures on servicewomen’s pregnancy outcomes: a scoping review. J Midwifery Womens Health. 2024;69(5):634-646. doi:10.1111/jmwh.13620
Peterson A, Hale W, Baker MT, et al. Psychiatric aeromedical evacuations of deployed active duty U.S. military personnel during operations Enduring Freedom, Iraqi Freedom, and New Dawn. Mil Med. 2018;183:649-658. doi:10.1093/milmed/usy188
Schmied EA, Highfill-McRoy RM, Larson GE. Mental health and turnover following an initial term of military service. Mil Med. 2012;177(7):766-772. doi:10.7205/milmed-d-11-00430

Reportable medical events at Military Health System facilities through week 36, ending September 6, 2025

Mon, 01 Dec 2025 00:00:00 Z

Total active component cases reported per week are displayed for the top 5 RMEs for the previous year. Each month, the graph is updated with the top 5 RMEs, and is presented with the current month’s (August 2025) top 5 RMEs, which may differ from previous months. COVID-19 is excluded from these graphs due to changes in reporting and case definition updates in 2023.

Authors’ Affiliation

Defense Health Agency, Disease Epidemiology Branch, Defense Centers for Public Health–Aberdeen

References

Armed Forces Health Surveillance Division. Armed Forces Reportable Medical Events. Accessed Feb. 28, 2024. https://health.mil/reference-center/publications/2022/11/01/armed-forces-reportable-medical-events-guidelines
Defense Manpower Data Center. Department of Defense Active Duty Military Personnel by Rank/Grade of Service. Accessed Feb. 28, 2024. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports
Defense Manpower Data Center. Armed Forces Strength Figures for January 31, 2023. Accessed Feb. 28, 2024. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports
Navy Medicine. Surveillance and Reporting Tools–DRSI: Disease Reporting System Internet. Accessed Feb. 28, 2024. https://www.med.navy.mil/navy-marine-corps-public-health-center/preventive-medicine/program-and-policy-support/disease-surveillance/drsi

Follow up testing among male U.S. Air Force basic trainees diagnosed with chlamydia or gonorrhea, 2017–2023

Sat, 01 Nov 2025 00:00:00 Z

Abstract

While female U.S. Air Force and Space Force basic military trainees are screened universally for gonorrhea and chlamydia, male basic trainees are tested only when symptomatic or upon patient request. Epidemiology and follow-up testing of male basic trainees who test positive for gonorrhea or chlamydia in training is unclear. All active duty male basic trainees at Joint Base San Antonio–Lackland who tested positive for gonorrhea or chlamydia from 2017 through 2023 (50 of 182,726 total male trainees, 0.03%) were matched, 1-to-1, by age and accession date, with active duty female basic trainees who tested positive for the same pathogen. Medical records from military hospitals and clinics were reviewed for follow-up testing within 12 months of the initial positive test and subsequent diagnoses for chlamydia and gonorrhea up to 3 years afterwards, or July 1, 2024, whichever occurred first. Among 50 male basic trainees, 30 (60%) reported symptoms when presenting for testing. Most cases (86%) were due to chlamydia. Only 56% (n=28) of male trainees had follow-up testing within 1 year, compared to 76% (n=38) of matched female basic trainees (OR 0.4, 95% CI: 0.17, 0.95). Low screening for chlamydia and gonorrhea among male basic trainees may contribute to reduced follow-up testing and represents a missed opportunity to identify infections, prevent transmission, and reduce the burden of infection in this population.

What are the new findings?

Male basic military trainees who tested positive for gonorrhea or chlamydia had follow-up testing rates significantly below guideline recommendations. Rates of future infections among male basic trainees were not, however, statistically lower than female trainee rates of future infections.

What is the impact on readiness and force health protection?

These findings support universal gonorrhea and chlamydia screening for male trainees at higher risk for infection to reduce the impact of untreated infections on military readiness for individuals and their partners, in addition to facilitating provision of available methods of sexually transmitted infection prevention.

Background

Service in the U.S. military has been associated with increased risk of sexually transmitted infections (STIs) such as gonorrhea and chlamydia.¹ Before basic military training (BMT), all potential enlistees undergo medical evaluation including HIV testing, to ensure they meet criteria for accession, but they are not tested for chlamydia^2-6 or gonorrhea. BMT is an 8-week training program that is the sole point for civilian entry into the enlisted ranks of the U.S. Air Force and Space Force. During BMT, all trainees have access to universal, no-cost health care at both primary care clinics and emergency care facilities on base.⁷ Because male BMT trainees are not screened for gonorrhea or chlamydia, they are only tested if they are symptomatic or request testing.

A recent study of universally screened male Air Force BMT trainees found similar overall rates of chlamydia with female Air Force BMT trainees, although most infections were asymptomatic.⁸ Women entering U.S. Air Force and Space Force BMT are universally screened for chlamydia and gonorrhea due to known long-term sequelae of untreated infections, previously documented high rates of positivity, and guidelines recommending universal female screening. Positivity rates among female BMT trainees are approximately 0.3% for gonorrhea and 5.0% for chlamydia. With the exception of the Army, all services require universal screening for female BMT trainees.⁷

Current U.S. Centers for Disease Control and Prevention (CDC) guidelines recommend testing for re-infections 3 months after a gonorrhea or chlamydia diagnosis, regardless of patient sex or risk factors for future infection.⁵ Additionally, guidelines recommend that men at high risk for STIs, such as men who have sex with men, should be screened at least annually for chlamydia and gonorrhea. Annual chlamydia screening is required by all services for female service members under age 25 years.⁷

While the screening disparity between male and female BMT trainees is evident, it is unclear how this may affect future testing and STI diagnoses for male trainees who test positive for chlamydia or gonorrhea during BMT. Previously evaluated 2006-2021 data from 5,022 female BMT trainees who tested positive for gonorrhea or chlamydia showed a high follow-up testing rate (69.7%) within 1 year, as well as a relatively high rate (15.9%) of positivity upon repeat testing.² This study investigated the incidence of gonorrhea and chlamydia in male Air Force and Space Force BMT trainees from 2017 through 2023 and compared follow-up testing and clinical outcomes with female BMT trainees.

Methods

This retrospective matched cohort study evaluated all active duty male BMT trainees who tested positive (i.e., cases) for gonorrhea or chlamydia at Joint Base San Antonio–Lackland during any point in their BMT from 2017 through 2023. Additionally, during this study period, from November 2021 through March 2022, 352 male BMT trainees as well as active duty, reserve, and National Guard members were tested for gonorrhea and chlamydia as part of a previously published universal screening study that did not evaluate follow-up testing, so they were also included in this study. All male cases were matched 1-to-1 with female BMT trainees (i.e., controls) by age, date of military accession, and pathogen testing positive during training to determine sex-based differences in follow-up testing.⁸ Urinary testing for gonorrhea and chlamydia was performed by nucleic acid amplification testing (Hologic, Marlborough, MA) throughout the entire study period.²

For all positive male cases, a retrospective chart review in the Joint Legacy Viewer and MHS GENESIS electronic health records was performed. These systems include all military hospital and clinic records, regardless of geographic location. Variables including patient demographics, indications for testing, and testing facility were collected for each case. While current CDC guidelines recommend follow-up testing for re-infection at 3 months, this study evaluated whether a patient underwent repeat testing within 12 months of a positive test.²

Chart reviews identified positive laboratory test results for gonorrhea and chlamydia in BMT trainees. Test results for 3 years after original gonorrhea or chlamydia diagnosis were reviewed, or until July 1, 2024 if a period of 3 years following original diagnosis had not elapsed by initiation of data collection, as that period of time was used for a previous study.⁹

Nominal variables were compared by Fisher’s Exact Test due to small sample size, and continuous variables were compared by a Mann-Whitney U test due to non-parametric data distribution. Standard odds ratios (ORs) with 95% confidence intervals (CIs) were also calculated. A p-value less than 0.05 was pre-determined to be statistically significant.

This study was reviewed by the 59th Medical Wing Human Protections Office and determined to be exempt from Institutional Review Board approval due to its retrospective nature, and thus, consent was not obtained from subjects.

Results

Of the 182,726 male BMT trainees from 2017 through 2023, 50 active duty male trainees (0.03%) tested positive for gonorrhea or chlamydia during their 8 weeks of training (data not shown). Most cases (n=43, 86%) were due to chlamydia, with the remainder positive for gonorrhea (Table 1). There were no cases of co-infection among male BMT trainees (Table 1). During the same period, 5-6% of female trainees screened positive for chlamydia, and 0.2–0.4% screened positive for gonorrhea (data not shown).

The median age of male BMT trainees was 20 years (IQR 19-21). Most cases (n=44, 88%) were detected in primary care settings, with a minority of cases (n=4, 8%) diagnosed in the emergency department. The median time in training until diagnosis was 12.5 days (IQR 8-27).

Thirty male trainees (60%) had symptoms on presentation for chlamydia and gonorrhea testing, with dysuria (n=20, 40%) and penile discharge (n=15, 30%) the most common (Table 1). Nine (18%) male trainees were tested as part of the previously reported screening protocol,⁸ while 10 (20%) were tested after being notified of STI exposure by a partner (data not shown). Four (8%) additional male BMT trainees were asymptomatically screened for chlamydia and gonorrhea after presenting to a medical provider for another medical problem, including 1 service member who tested positive during HIV screening (data not shown).

Of the male BMT trainees with chlamydia or gonorrhea, 28 (56%) had repeat testing in 1 year, with 5 testing positive for chlamydia and 1 for gonorrhea (Table 2). Male trainees had statistically significant lower follow-up testing within 1 year compared to female trainees (56% vs. 76%; OR 0.41, 95% CI 0.17, 0.95) (Table 2). Despite this difference in follow-up testing, there was no statistically significant difference in chlamydia and gonorrhea diagnoses during the next 3 years: a total of 8 diagnoses among men versus 12 among women (OR 0.6, 95% CI 0.22, 1.63) (Table 2).

Discussion

This retrospective matched cohort study evaluated 50 male Air Force and Space Force BMT trainees who tested positive for gonorrhea or chlamydia from 2017 through 2023. The majority of male BMTs who tested positive in this study presented for testing due to symptoms consistent with an STI. Only 56% of the men in this study received follow-up testing within 1 year.

When compared to prevalence rates of gonorrhea and chlamydia among the universally-screened female BMT population, the rate observed among the male BMT trainee population in this study is much lower than expected. When universally screened, 4.8% of male BMT trainees tested positive for chlamydia.⁸ While the universal screening study included National Guard and reserve trainees in addition to active duty personnel, if that rate were applied to the population in this study, 8,771 cases of chlamydia would be expected among male BMT trainees. Given that only 43 cases of chlamydia were diagnosed in this study, it appears as though only 0.5% of expected cases of chlamydia were captured in this cohort. Notably, 9, or nearly 20%, of the cases in this study were identified through the previously published universal screening study. These results show that relying upon symptoms or partner notification likely missed thousands of infectious in the male BMT population.

Despite universal access to medical care, only 54% of male BMT trainees who tested positive for an STI in this study were re-tested within a year. CDC guidelines^5,11 recommend repeat testing in 3 months post-diagnosis due to the high risk of re-infection with the same or new STI pathogen. Similar to previous reports of follow-up testing in women in basic training, a relatively high positivity (18%) results on repeat testing. This finding suggests that a population with a bacterial STI who undergoes testing might be at greater risk for future infections in a male trainee population, and that there may be benefit from interventions such as Doxycycline Post-Exposure Prophylaxis (DoxyPEP), which has shown benefit in other populations, even decreasing incidence within a population.

There are several challenges related to STI testing in a military trainee population. First, due to the low reported incidence of STIs in BMT men, even if symptomatic, they are often not tested for bacterial STIs. Additionally, there is significant stigma related to STI positivity throughout the military that may be amplified in the BMT environment, the first stage of a service member’s military career, during which trainees experience significant stressors unrelated to their sexual health. Other unique challenges within the military population can contribute to lower than ideal follow-up testing rates. The majority of BMT trainees are assigned to a different duty station after graduation, resulting in lack of continuity of care that likely contributes to diminished follow-up testing, although notably, female BMT trainees with gonorrhea or chlamydia who moved to a different military base evinced a higher follow-up rate than women who stayed on the base where they originally tested positive. Finally, military members often have a career-long focus on maintaining mission readiness, and preventive medical care, which can potentially change an individual’s ‘mission ready’ status, is often avoided, as described in other military populations.^13,18

There are limitations to consider when interpreting these results. First, initial diagnoses and the start of data collection occurred within close temporal proximity. Although periods of time for follow-up testing were artificially shortened for some individuals, they should be similar for paired individuals, as matching was by accession date.

Second, the periods of service for men and women with chlamydia or gonorrhea may be different, which was not captured in this study and could lead to differences in observational time between men and women. Future studies could use person-time rates to adjust for varying follow-up durations.

In addition, patients empirically treated without testing were not captured, and the methodology did not allow ascertainment of the total number of male BMT trainees who tested negative for gonorrhea and chlamydia, and thus testing rates could not be determined.

This study did not evaluate extragenital testing, which has lower uptake compared to genital testing²² and could have identified more individuals, resulting in more conservative estimates of infection.

Furthermore, the small sample of 50 men and 50 women may have limited this study’s power to detect statistically significant differences between the 2 groups. Testing records before or after BMT for patients who did not test positive during the study period were not available for review, which likely contributed to an overall under-calculation of follow-up testing rates and new infection rates for both groups of BMT trainees.

There are potential benefits as well as drawbacks of implementing a universal STI screening program for male service members in the U.S. Air Force. While the true incidence of gonorrhea and chlamydia in this population is likely under-estimated due to asymptomatic infections and lack of routine screening, a screening program could identify individuals at risk and inform them of preventive health strategies. Furthermore, studies suggest that universal screening can be cost effective through the prevention of long-term health issues in female partners. Universal BMT male screening is not currently in place, however, due to the lack of long-term complications in men from untreated infections, its cost, and the administrative burden of testing. Despite these challenges, STI testing remains important for interrupting disease transmission, which has the potential to affect mission readiness through complications in female partners as well as increased HIV risk in both sexes.

Author Affiliations

Department of Medicine, Brooke Army Medical Center, Joint Base San Antonio–Fort Sam Houston, San Antonio, TX: Capt Powers, Maj Marcus; Trainee Health Surveillance, 559th Medical Group, Joint Base San Antonio-Lackland, TX: Lt Col Winkler, Brig Gen (ret) Casey, Ms. Osuna, Ms. Jung; Department of Medicine, Uniformed Services University of Health Sciences and Infectious Diseases Service, Brooke Army Medical Center: Maj Marcus

Disclaimers

The views expressed herein are those of the authors and do not reflect official policy nor position of the Defense Health Agency, Brooke Army Medical Center, the Department of Defense, or the U.S. Government.

The data that support the findings of this study are available on request from the corresponding author. All data are freely accessible. This study was reviewed by the Defense Health Agency San Antonio Market Institutional Review Board, protocol FWH20240006E, and determined to be exempt and informed consent not necessary.

References

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Townsend LC, Stahlman SL, Escobar JD, et al. Positivity and follow-up testing of Chlamydia trachomatis and Neisseria gonorrhoeae infections in universally screened female basic military trainees. Sex Transm Dis. 2025;52(3):176-180. doi:10.1097/olq.0000000000002099
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