Government employees and retirees owed $3.54 billion in unpaid taxes last year, $220 million more than in 2013, according to the most recent IRS data.

As of Sept. 30, nearly 305,000 federal workers and retirees owed back taxes, down from 318,000 the previous year.

The IRS reported a delinquency rate of 3.1 percent for the 9.8 million federal workers and retirees, a 3.3 percent decrease from 2013.

Among executive departments, the Department of Housing and Urban Development had the highest delinquency rate, at 4.74 percent, followed by the Department of Veterans Affairs, with a 4.44 percent delinquency rate.

Retired members of the military were the biggest tax offenders, owing a total of 1.57 billion with a delinquency rate of $4.04 percent. Civilian employees followed close behind, owing $1.14 billion with a 3.99 percent delinquency rate.

In the House of Representatives, more than 500 employees, about 5 percent, owed $6.7 million in back taxes. In the Senate, 220 workers, or 3.5 percent, owed the IRS about $2 million.

"It is disconcerting that federal civilian employees owe more than $1 billion in back taxes," said Rep. Jason Chaffetz, R-Utah, chairman of the Oversight and Government Reform Committee, reported The Associated Press. "These employees are not exempt from their civic responsibility to fulfill tax obligations, and those who refuse to pay what they owe should be held accountable."

On Wednesday, Chaffetz's committee passed the Federal Employee Tax Accountability Act of 2015, which prevents agencies from hiring tax delinquents.

The bill requires individuals applying for a federal job to submit proof that they don't owe taxes. It also gives agencies the authority to fire current federal employees have tax debt.

The IRS said it doesn't have the general public's tax data ready yet, but historically, the delinquency rate for the general public has been between 8 percent and 9 percent, which is much higher the rate for federal employees, AP reported.