The Government Accountability Office is the audit, evaluation and investigative agency of the United States Congress and part of the legislative branch. It was created by the Budget and Accounting Act of 1921 as the General Accounting Office and took its present name in 2004 under the GAO Human Capital Reform Act. Headed by the Comptroller General of the United States, it examines how federal agencies spend public money and run their programs, working independently and on a nonpartisan basis in support of congressional oversight, at the request of members and committees or under mandates written into law.

Its best-known entry into UFO history came at the request of Representative Steven Schiff, a New Mexico Republican who had made inquiries to the Defense Department in 1993 about the Roswell crash of July 1947. Concerned, as the office put it, that the department "may not have provided you with all available information on the crash," Schiff asked it to determine the reporting requirements for such air accidents and to identify any government records on the event. Investigators examined classified and unclassified records from July 1947 through the 1950s held by the Defense Department, the FBI, the CIA and the National Security Council, and wrote to other agencies for any further holdings.

The resulting report, GAO/NSIAD-95-187, was issued on 28 July 1995. It found that Roswell Army Air Field administrative records from March 1945 through December 1949, and its outgoing messages from October 1946 through December 1949, had been destroyed, and that the disposition form did not say who destroyed them, when or under what authority. Only two 1947 records surfaced: the July history of the 509th Bomb Group and the air field, which said the "flying disc" turned out to be a radar tracking balloon, and an FBI teletype of 8 July describing an object that resembled a high-altitude weather balloon with a radar reflector. The Defense Department referred the office to the Air Force's 1994 report attributing the debris most likely to a Project Mogul balloon train, and a CIA search found no records on the crash.

Congress returned the office to the subject in the defense authorization act for fiscal 2023, which directed the Comptroller General to identify appropriately cleared staff "to audit the historical record report process" of the All-domain Anomaly Resolution Office, share findings with that office quarterly and brief the intelligence and defense committees and congressional leadership twice a year; the fiscal 2025 act amended the provision. In September 2026 the WEAPONIZED Podcast reported that two GAO investigators were visiting military bases to ask service members about UAP sightings, how their commands handled the reports, how witnesses were treated and whether AARO documented their accounts, and that the findings would not be made public.

The 1995 search remains the legislative branch's principal independent review of the Roswell records, and its finding that air field files were destroyed without a recorded authority is still cited in debate over the case. Three decades later the office again holds a statutory audit role over the Pentagon's account of past government involvement with UAP.