IRS Struggles with $696 Billion Tax Gap as High-Income Nonfiler Cases Stall Amid Staffing Cuts

The U.S. tax gap—the difference between taxes owed and those paid on time—reached a projected $696 billion for tax year 2022, according to IRS projections, with nonfiling accounting for $63 billion or 9% of the total.[1][2] A Treasury Inspector General for Tax Administration (TIGTA) audit highlighted persistent delays in pursuing high-income nonfilers: nearly 39,000 cases involving taxpayers earning $400,000+ remained in first-notice status as of mid-2025, representing an estimated $15.7 billion in potential assessments, with 9,463 cases still unassigned in the enforcement queue by December 2025.[3][4] The IRS also issued erroneous notices to nearly 5,000 taxpayers who had already filed returns.[5]

These enforcement shortfalls stem from reduced resources. The Inflation Reduction Act's supplemental funding was cut, and the Trump administration oversaw significant IRS workforce reductions—approximately 21% overall, with steeper drops in enforcement and collection staff—leading to a roughly 30% decline in individual examinations.[6][7] Broader context includes over 571,000 current and retired federal employees owing $6.3 billion in unpaid taxes as of FY 2024, a 43% increase in delinquent individuals since 2021.[8]

The nonfiler population nearly doubled from 2015 to 2022, underscoring systemic challenges in collection despite record overall revenue. TIGTA reports emphasize that prioritizing these cases could yield substantial returns, but coordination and staffing constraints have limited progress.