Over a three-year period, the Defense Department put about 8,600 employees on leave for one to three months, nearly 900 for three months to a year and 123 for more than a year, a GAO report said. (Kevin Lamarque/Reuters)

Tens of thousands of federal workers are being kept on paid leave for at least a month — and often for longer stretches that can reach a year or more — while they wait to be punished for misbehavior or cleared and allowed to return to work, government records show.

During a three-year period that ended last fall, more than 57,000 employees were sent home for a month or longer. The tab for these workers exceeded $775 million in salary alone.

The extensive use of administrative leave continues despite government personnel rules that limit paid leave for employees facing discipline to “rare circumstances” in which the employee is considered a threat. The long-standing rules were written in an effort to curb waste and deal quickly with workers accused of misconduct.

And the comptroller general, the top federal official responsible for auditing government finances and practices, has repeatedly ruled that federal workers should not be sidelined for long periods for any reason.

But a report by the Government Accountability Office, first made public by The Washington Post on its Web site Monday, found that 53,000 civilian employees were kept home for one to three months during the three fiscal years that ended in September 2013. About 4,000 were idled for three months to a year and several hundred for one to three years. This is the first time the government has calculated the scope and cost of administrative leave.

Auditors found that supervisors used wide discretion in putting employees on leave, including for alleged violations of ­government rules and laws, whistleblowing, doubts about trust­worthiness, and disputes with colleagues or bosses. Some employees remain on paid leave while they challenge demotions and other punishments.

While the employees stayed home, they not only collected paychecks but also built their pensions, vacation and sick days and moved up the federal pay scale.

“Six months went by, and we didn’t hear anything,” said Scott Balovich, who was put on administrative leave from his IT systems job at the National Oceanic and Atmospheric Administration in Alaska. “You’re so anxious. You don’t know if you’ve got a job. You’re getting paid, but it’s no vacation.”

Balovich, who makes $108,000 a year, was paid not to work while investigators examined how pornographic images had gotten onto his computer hard drive. He ultimately was cleared of any personal involvement and returned to his job last week. His attorney, Debra D’Agostino, a founder of the Federal Practice Group, said he “got stuck in the inertia of bureaucracy.”

The GAO report almost certainly understates the extent and cost of administrative leave because the figures examined by the auditors were incomplete. The numbers reviewed account for only about three-fifths of the federal workforce since not all government agencies keep track of the practice.

The Office of Personnel Management rule book lists dozens of reasons for allowing paid leave, such as donating an organ, house-hunting before a job transfer and attending the funeral of a relative in the military. Snow days also are permitted.

But these require only a few hours or days — not the months and years that the GAO discovered are common at more than 100 federal agencies.

“It’s not authorized by any law,” said Sen. Charles E. Grassley (R-Iowa), referring to the cases that drag on. “Bureaucrats are abusing it.”

Grassley, Sen. Tom Coburn (R-Okla.) and Rep. Darrell Issa (R-Calif.), who chairs the House Committee on Oversight and Government Reform, requested the GAO report. Grassley is working with Sen. Jon Tester (D-Mont.) on legislation that would narrowly define the circumstances in which employees can be kept home. Pay would be limited to a few days, congressional aides said.

OPM regulations, which govern personnel practices across the government, say an employee faced with a proposed disciplinary action “will remain in a duty status” except in “rare circumstances” when he or she poses a threat to himself or others, is at risk of stealing government property or jeopardizes “legitimate government interests.” That rule, which dates to 1980, was adopted on the heels of the last major shake-up of the federal civil service as part of a push to curb waste and fraud and make agencies more accountable to taxpayers.

Even earlier than that, the comptroller general began to make clear that extended paid leave was not appropriate. As long ago as 1958, for instance, the comptroller general said that an employee under investigation for wrongdoing “may be relieved from duty and continued in a pay status for 24 hours or so.” That was the first of a dozen such rulings issued by the comptroller general since then.

At many private companies, paid leave is rarely used, if at all, and lasts a few days at most, personnel experts said. An employee accused of wrongdoing either stays at the office and is reassigned or is suspended without pay.

“The private sector is focused on operating efficiently,” said Kathy Albarado, chief executive of Helios HR, a consulting firm based in Northern Virginia. Many of Helios’s clients are government contractors that cannot bill the government for salaries if employees are on paid leave. “So they’re motivated to ensure they’re resolving any dispute quickly,” Albarado said.

Shortly before Balovich went back to work at NOAA, the agency official in charge of his case apologized in an e-mail for keeping him at home so long. “I agree that the process has been way, way too lengthy,” Jim Balsiger, the regional administrator for NOAA fisheries in Alaska, wrote to him, saying the case had to be processed through various government offices.

Balsiger’s deputy, Doug Mecum, said in an interview: “We weren’t in control of the timeline. People and players above us were in control.”

A NOAA spokesman, citing privacy laws, declined to comment on the specifics of Balovich’s case.

In another case, a former acting inspector general at the Department of Homeland Security was put on paid leave in April while he was investigated for allegedly misusing his office and soft-pedaling reports about misbehavior by Secret Service agents. Before he was sent home, Charles Edwards resigned his post and transferred to a different job in the department.

DHS spokeswoman Marsha Catron confirmed that Edwards remains on leave but declined to say how long it will last. Edwards did not respond to a telephone message left at his home seeking comment.

“Unless you think somebody is going to get a gun and shoot people, then send them to work,” said Jeffrey Neal, a longtime federal personnel manager who retired in 2011 as the DHS human capital chief. “If they’re sitting there, you’re going to be reminded, ‘We have to do something about Betty Lou.’ ”

There is no law addressing administrative leave. Brenda Roberts, OPM deputy associate director for pay and leave, said agencies have used their own discretion in putting workers on paid leave.

The OPM has at times given guidance to managers across government on how it should be used, she said, adding that “we’ve always stated it’s for brief periods of time.”

Spokesmen for several agencies, when asked why they sidelined hundreds or thousands of employees for long periods, said they rely on the OPM for guidance.

“Administrative leave . . . is generally limited to special situations involving brief absences,” Defense Department spokesman Nathan Christensen said in a statement. It “may, in limited circumstances, be granted on an extended basis for situations such as security clearance reviews, or other due process situations where such leave is deemed to be in the interest of the Department.”

The GAO found that the Defense Department put about 8,600 employees on leave for one to three months, nearly 900 for three months to a year and 123 for more than a year.

In a move rare for federal agencies, the Justice Department has taken steps to rein in the use of administrative leave, limiting it to 10 workdays unless the assistant attorney general for administration approves a longer period.

“It became very clear to us that managers were putting people on administrative leave because it was the easiest thing to do,” said Robert Diegelman, who wrote the policy in 2002, when he was a high-level official at the Justice Department. “Too often it went on forever.”

That’s how it seemed for Hayley Dikeman, a wildlife biologist at the U.S. Fish and Wildlife Service in Tulsa who was sent home for six months after she disagreed repeatedly with an environmental decision by the agency and argued with her supervisors. She said she was upset that the agency had allowed a company in Oklahoma to lay a utility line without first studying how it might affect the habitat of an endangered beetle.

The biologist said she questioned the agency’s integrity and accused it of giving industry special treatment. Agency officials said she exhibited “disrespectful” behavior toward her supervisors, she recalled. She was suspended without pay before being put on paid leave. “They just didn’t want to deal with her,” said her attorney, Debra Roth.

Claiming she was a whistleblower, Dikeman took her case to the Office of Special Counsel, which began investigating whether she had suffered from retaliation. She said that a separate internal investigation found in her favor and that she is now back at work.

Jessica Kershaw, spokeswoman for the Interior Department, Fish and Wildlife’s parent agency, said in a statement that it had “completed its review and made recommendations for appropriate disciplinary and corrective actions. Because these recommendations are subject to further review and negotiations of a privileged nature, we are unable to comment further.”

Roth, who is general counsel for the Senior Executives Association, which represents 7,000 government executives, said the OPM is partly responsible for the abuses of administrative leave.

The “OPM has turned a blind eye to this, and it’s shameful,” she said. “There’s no sense of urgency.”