The U.S. federal government agencies, such as the Departments of Defense and State, procure and employ PMSCs, and these actions are subject to congressional oversight. Oversight is accomplished by congressional committees or subcommittees that examine (1) how the agency spends its budget; (2) the substance of the agency's work; or (3) the general operations of the agency. For each federal agency, one of each of these three types of committees exists in both the House and Senate. Each has its own guidelines, within which each committee adopts its own rules. However, as a general matter most committees review agency action through the use of hearings. Witnesses selected by committee members usually testify on a set subject matter and response to questions by Congress.

While most hearings are open to the public and transcripts of the proceedings later published, some hearings are closed because of national security concerns, and those transcripts are unavailable. The publicly-available hearing transcripts that pertain to agency use and regulation of PMSCs appear below, organized by congressional committee.

• U.S. Senate Committee on Appropriations
• U.S. Senate Armed Services Committee
• U.S. Senate Committee on Foreign Relations
• U.S. Senate Committee on Homeland Security and Governmental Affairs
• U.S. Senate Committee on the Judiciary
• U.S. Senate Democratic Policy and Communications Committee
• U.S. House of Representatives Committee On Appropriations
• U.S. House of Representatives Armed Services Committee
• U.S. House of Representatives Committee on Oversight and Government Reform
• U.S. House of Representatives Committee on Foreign Affairs
• U.S. House of Representatives Committee on the Judiciary