Federal employees owe more than $1 billion in income tax

But on Capitol Hill, 684 employees, or almost 4 percent, of the 18,000 congressional staffers owed taxes in 2010 – a jump of 46 workers from 2009. Four percent of House staffers owed $8.5 million and 3 percent of Senate employees owed $2.1 million, the IRS said.

At the Executive Office of the President – encompassing 1,800 employees of the West Wing, the Office of Management and Budget, the National Security Council and the Office of U.S. Trade Representative, among others – 36 staffers, or 2 percent, owed a $833,970. The amount owed increased by almost $3,000 from the previous year.

Civilian employees of the Defense Department — the federal government’s largest employer — fared the worst. More than 25,600 workers at the departments of the Army, Air Force and Navy owed a combined $225.7 million, while another 4,600 civilian Pentagon employees owed $39.4 million.