Federal employees have fallen further behind on their taxes, with their combined overdue debt to the government rising last year to its highest level in a decade.

Civilian federal personnel owed more than $1.14 billion in back taxes in 2014, according to Internal Revenue Service data that the House Oversight and Government Reform Committee released this week.

Despite the higher dollar amount, fewer federal employees were tax delinquent last year compared with 2013. The number dropped 2 percent to 113,800 workers, representing about 4 percent of the U.S. government’s 2.85 million-strong civilian workforce, including postal personnel.

“It is disconcerting that federal civilian employees owe more than one billion dollars in back taxes,” Rep. Jason Chaffetz (R-Utah), the chairman of the committee, said in a statement Tuesday. “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.”

Data: IRS. (Graphics by Josh Hicks/The Washington Post)

Among executive departments, Housing and Urban Development finished last year with the highest rate of delinquency, with 4.7 percent of the agency’s personnel owing back taxes. Veterans Affairs had the second-highest rate at 4.4 percent.

The Treasury Department fared best, with a delinquency rate of 1.2 percent. The Energy Department followed with a rate of 2.1 percent.

Many congressional employees also have struggled to pay their taxes. The data shows that about 5 percent of House staff and 3.5 percent within the Senate were delinquent last year.

Additionally, 1.4 percent of active-duty military personnel and 2.4 percent of reserve troops owed back taxes in 2014.

The latest numbers come less than two months after Sen. Pat Roberts (R-Kan.) proposed legislation to end bonuses for federal employees who owe outstanding federal tax debt. The measure would allow exceptions for personnel who have experienced economic hardship or have agreed to payment plans.

An inspector general’s report in April revealed that the IRS had doled out more than $1 million in financial awards to hundreds of tax-delinquent IRS employees in recent years.