"The federal government faces an unsustainable long-term fiscal path that poses serious economic, security, and social challenges if not addressed," the report said on Thursday.
The government's accumulated debt is projected to grow faster than the entire economy, reaching 200% of GDP by 2050 if revenue and spending policies are unchanged, the report states.
"Large budget deficits drive the growing debt, as Medicare and Social Security spending outpace revenue," the GAO said.
Government interest spending as a share of GDP will reach an all-time high by 2030, in part due to rising interest rates, the report added.