Records (or portions of records) will be disclosed unless that disclosure harms an interest protected by a FOIA exemption. The nine exemptions are cited in the Act as 5 U.S.C. 552(b)(1) through (b)(9):

• Exemption (b)(1) records currently and properly classified in the interest of national security.
• Exemption (b)(2) records related solely to internal personnel rules and practices of an agency.
• Exemption (b)(3) records protected by another law that specifically exempts the information from public release.
• Exemption (b)(4) trade secrets and commercial or financial information obtained from a private source which would cause substantial competitive harm to the source if disclosed.
• Exemption (b)(5) internal records that are deliberative in nature and are part of the decision making process that contain opinions and recommendations.
• Exemption (b)(6) records which if released, would result in a clearly unwarranted invasion of personal privacy.
• Exemption (b)(7) investigatory records or information compiled for law enforcement purposes.
• Exemption (b)(8) records for the use of any agency responsible for the regulation or supervision of financial institutions.
• Exemption (b)(9) records containing geological and geophysical information (including maps) concerning wells.

Exclusions

In certain circumstances, the acknowledgement of the existence of a record, in and of itself, can produce consequences similar to those resulting from disclosure of the record itself. To avoid this type of problem, the 1986 amendments established three record exclusions. If these records are requested, the agency may respond that there are no dissoluble records responsive to the request.

• The (c)(1) exclusion authorizes federal law enforcement agencies, under specified circumstances, to shield the very existence of records of ongoing investigations or proceedings by excluding them entirely from FOIA’s reach.
• The (c)(2) exclusion provides that "whenever informant records maintained by a criminal law enforcement agency under an informant's name or personal identifier are requested by a third party, the agency may treat the records as not subject to the requirements of FOIA unless the informant's status has been officially confirmed.”
• The (c)(3) exclusion pertains only to certain law enforcement records that are maintained by the Federal Bureau of Investigation.