Americans failed to pay $688 billion in taxes on their 2021 returns, a record level, according to a new estimate from the IRS. The agency said that it is taking “urgent” steps to increase compliance such as auditing more high-income taxpayers as well as businesses and partnerships.

The $688 billion estimate reflects the first time the IRS is providing information about the so-called tax gap on an annual basis, with the agency noting in a Thursday statement that it plans to continue providing the data on a yearly basis. The number reflects an increase of more than $138 billion from estimates for tax years 2017 to 2019, the agency said.