The U.S. Government Accountability Office (GAO) is an independent, nonpartisan agency that works for Congress. Often called the "congressional watchdog," GAO examines how taxpayer dollars are spent and provides Congress and federal agencies with objective, reliable information to help the government save money and work more efficiently.
For example, they identified $214.7 billion in financial benefits in fiscal year 2019—a return of about $338 for every $1 invested in us. They also identified 1,418 other benefits that led to program and operational improvements across the government. Read the press release
about these record numbers.