The federal government spent more than $775 million over three years on salaries for workers put on administrative leave, according to a study first reported by The Washington Post.

More than 57,000 employees were paid to stay home for a month or longer from October 2010 to September 2013, according to a forthcoming Government Accountability Office (GAO) report.

They earned pensions, vacations, sick days and raises as well as their paychecks, while the government investigated claims of misconduct or took steps to return them to work. The vast majority were out between one to three months, but about 4,000 stayed home for three months to a year. Some even received paid leave for more than a year.

The Office of Personnel Management’s handbook doesn’t permit administrative leave except in rare circumstances, according to the Post. The agency’s handbook only allows it if the person could become a threat, or in short-term situations including organ donation or attending a funeral of a family member who served in the military.

But that hasn’t stopped the federal government from extending it for months in some cases, upsetting lawmakers.

“It’s not authorized by any law,” Sen. Chuck GrassleyCharles (Chuck) Ernest GrassleyGOP senators eager for Romney to join them Five hurdles to a big DACA and border deal Grand jury indicts Maryland executive in Uranium One deal: report MORE (R-Iowa) told the Post. “Bureaucrats are abusing it.”

Grassley, along with Sen. Jon TesterJonathan (Jon) TesterEMILY’s List president: Franken did 'right thing for Minnesota' Reforming veterans health care for all generations of veterans Trump and Republicans deliver gift that keeps on giving for Americans MORE (D-Mont.), wants to codify a paid leave requirement that limits the practice.

Three State Department officials, and another who later resigned, were placed on administrative leave for months after the agency’s Accountability Review Board criticized them over the Benghazi terror attacks.

Former Internal Revenue Service official Lois Lerner also received paid leave before her eventual resignation.