Mapping the maze where the IRS could find billions in unpaid taxes

In 2021, the difference between what U.S. taxpayers owed the federal government and what they paid hit nearly $700 billion. This "tax gap" has been growing for years while the Internal Revenue Service's budget has shrunk, declining by 18% between 2010 and 2021. The audit rate for millionaires fell by more than 70% in roughly that same period.