KEY POINTS
  • The Treasury Department estimates that the U.S. tax gap will balloon to $7 trillion over the next decade.
  • Deputy Assistant Secretary Mark Mazur says that a larger gap causes higher tax rates elsewhere and erodes revenue to fund the nation's fiscal priorities.
  • Mazur recommended lawmakers support provisions that would help bulk up the IRS, which has seen its budget cut 20% over the last decade. 
The Internal Revenue Service building in Washington.

The Treasury Department estimates that the difference between how much Americans owe in taxes and how much they actually pay will balloon to $7 trillion over the next decade.

In prepared remarks, Deputy Assistant Secretary Mark Mazur told Congress on Thursday that the so-called tax gap will only worsen over the next several years without more funding from lawmakers.