GAO
Definition
The Government Accountability Office (GAO) is a nonpartisan agency that works for Congress, auditing and investigating how federal agencies spend money and run programs. It is often called the "congressional watchdog" and produces reports requested by lawmakers or required by law.
Why it matters
GAO reports give Congress independent, fact-based ammunition to challenge agency claims, but GAO can only investigate what a committee requests or a statute mandates, so its oversight capacity depends on Congress actually asking. GAO also issues formal legal opinions, including on whether the executive branch is illegally withholding congressionally appropriated funds, known as impoundment, which have become a live flashpoint in recent budget disputes.
Seen in the wild
GAO reported that its work produced $62.7 billion in financial benefits for the federal government in fiscal year 2025, along with 1,295 documented non-financial improvements across programs including veterans' services and public safety.1