Despite the tax cuts that take effect this year, more than 30 million taxpayers could owe money to the government next year, according to a Government Accountability Office report based on a simulation run by the Treasury Department. Taxes for more than a fifth of Americans (21 percent) could be underwithheld, meaning that their employer hasn’t taken enough money out of their paychecks to cover taxes.
Had there been no change in the tax law, 18 percent would have been underwithheld. That’s 3 million fewer people. Six percent of taxpayers are expected to break even next year, and the remainder will get some sort of refund.
So why might more Americans owe taxes next year? The IRS and Treasury Department had “limited documentation” for how it updated the withholding tables, according to the GAO report. And employees in high-tax states - like New Jersey - may be affected by the new limitations on state and local tax deductions, which would increase their tax burden.