Senate Finance Committee Chair Ron Wyden said the IRS was asleep when it came to handling Donald Trump's tax returns.
Wyden promised to work to reform the presidential audit program.
The IRS only started one mandatory audit of Trump's personal income tax returns during his four years in the White House, despite the agency's rules requiring annual audits of the president's tax returns.
The sole mandatory audit of Trump's 2016 tax return was not completed while he was in office according to the House panel's investigation.
Wyden said there was no excuse for the failure to conduct the required presidential audits.
Resource issues or fear of political retaliation from the White House may have contributed to the lapse here.
CNBC requested a response from the IRS on Wyden's statement.
The report on the presidential audit program was released after the Democrats on the Ways and Means Committee voted to redact Trump's federal income taxes. The committee voted to keep Trump's tax information out of their hands after a yearslong legal battle.
Trump refused to release his tax returns when he was running for president and after he won the election. Fact-checkers have reported that Trump could have released the returns despite his claims that he was restricted from doing so because of an IRS audit.
Trump tried to stop Congress from getting years of his taxes, but the Supreme Court turned him down. On Tuesday, a report gave a summary of Trump and his wife's tax returns for the years 2015 through 2020. The report showed that Trump and his wife paid zero federal income taxes in 2020.
The leak of Nancy Pelosi and her husband's tax returns was slammed by Steven Cheung as proof that Democrats are playing a political game. Cheung said that if this injustice can happen to President Trump, it can happen to everyone.
Wyden argued that Trump's tax returns showed the flaws of the tax code and consequences of the fight to gut the IRS.
The issues are bigger than Donald Trump. Hundreds of partnership interests, highly-questionable deductions, and debts that can be shifted around to wipe out tax liability are likely to be found in Trump's returns.
He said that if you are more likely to get struck by lightning than have your partnerships audited, then all of this will go completely undetected.
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