Lawmakers are concerned. "The agency has the same number of employees as it did in 1970, when the country's population and the economy were a fraction of the size they are today,"

At the end of the 2021 tax filing season in December, the IRS still had about 10.5 million returns to process. Electronically-filed returns can be processed in 21 days.

Erin Collins, National Taxpayer Advocate at the Internal Revenue Service, said the IRS has faced a variety of obstacles, including the COVID-19 pandemic's impact

"This past year was the most challenging year that taxpayers and tax professionals have ever experienced," she said. "Millions of taxpayers are confused.

On customer service, only 11% of the 195 million people who called the IRS for help last year managed to speak to a human being, and the average wait time for a phone call