The annual report from the federal Office of Taxpayer Advocate released Wednesday found that in the 2019 fiscal year, the IRS was late in sending legitimate refunds to many taxpayers and failed to answer the majority of phone calls from taxpayers. The agency also failed to collect billions in unpaid taxes.

The Taxpayer Advocate’s role — while inside the IRS — is to ensure taxpayer rights are fairly represented. The Advocate’s report found that the IRS is one of the lowest performing federal agencies in terms of customer service. The agency answered only 29 percent of the 100 million telephone calls it got during the 2019 fiscal year.

The IRS has increased the online tools and assistance it provides. But other forms of live support, such as Taxpayer Assistance Centers, have dwindled.

The IRS budget has been reduced by about 20 percent since 2010, after adjusting for inflation. And the number of full-time employees has declined by about 22 percent during that time. Meanwhile it had to manage a sweeping overhaul of federal tax law.

While the advocates office said the budget problem is at the core of the agency’s shortcomings, it also noted some could be attributed to “a culture in which the agency focuses on its own priorities without adequately factoring in the needs of taxpayers.”

The IRS has been unable to collect an annual average of about $381 billion in unpaid taxes between 2011 and 2013 period. This suggest each U.S. household is effectively paying $3,000 to subsidize noncompliance by others.

Additionally, many taxpayers who file legitimate returns waited weeks or months for a return in the past year because of a new fraud filter that flagged and stopped the processing of nearly 1.1 million returns. Ultimately though, its false positive rate was 71 percent, meaning that 71 out of every 100 refunds stopped were eventually determined to be legitimate.

The report comes as the IRS is developing a new strategic plan as part of the Taxpayer First Act, which became law on July 1. The law aims to broadly redesign the IRS and strengthen taxpayer rights. The agency must send its plan for how to do so to Congress in the fall.