The Federal Emergency Management Agency has informed employees who have worked extra hours battling a record wave of natural disasters in 2017 that they may have to pay back some of their overtime.

Federal law caps some federal employees' premium pay and permits agencies to recover money paid in excess of the maximum from future paychecks. FEMA says the extraordinary year of hurricanes, wildfires and other disasters means it may have to take that step.

"This year's unprecedented hurricane season led to a record-setting length of national activation," the agency said in an e-mailed statement. "Due to the extended work hours involved in supporting disaster recovery and response efforts for multiple storms, some employees have been affected by the annual maximum earnings ­limitation."

The agency last month sent employees a Frequently Asked Questions document saying that those who hit the annual cap because of the number of extra hours they've worked "may still be ordered to perform work without receiving further compensation," and would "continue to receive their regular base pay regardless of whether they exceed the annual premium pay cap or not."

Then, it said, "A bill will be determined and established for any premium pay amounts over the annual premium pay cap and the employee will be notified and billed in 2018 for that amount."

The issue arises amid broader reckoning at FEMA. On Nov. 30, the agency's administrator Brock Long told a House Appropriations subcommittee that staff were "tapped out" following record activation. "FEMA was never designed to be the first or only respondent in a disaster, but we often find ourselves in that situation," he said.

According to FEMA, there is a pool of about 500 employees whose compensation the agency is monitoring because they are at risk of exceeding the cap. Those employees are all exempt from the federal Fair Labor Standards Act and generally are toward the upper end of the agency's pay scale.

One FEMA employee, who asked not to be identified, said workers have voiced concerns to agency management about the issue. Billing staff or docking pay could reduce the willingness of FEMA employees or other Homeland Security staff to sign up for ­deployments in the future, she said.

The federal Office of Personnel Management, which handles federal workforce human resources, said the ceiling on annual compensation was out of its hands.

"The premium pay caps are statutory, and OPM does not have authority to waive or modify the premium pay caps," the agency said in an e-mail.

Under the law, an executive branch employee's premium pay — which includes overtime — combined with basic pay can't exceed the maximum rate of basic pay for certain categories of employees. An e-mail to staff from FEMA Nov. 2 offered the example of a category of employees based in Washington, D.C., who this year get a regular salary of $153,730; for those workers, Congress has capped the premium pay they can receive, including for working extra hours, at $7,636.40.

Along with the annual cap, there is also a ceiling on how much overtime compensation employees can receive each two-week period, but agencies have the discretion to waive that one, as the Department of Homeland Security did this year for hurricane relief — contributing to the annual cap issue.

"Employees who have exceeded the annual premium pay cap will be contacted and provided options on the overpayment process," the agency told its employees. They will be able to give back the money via payroll deduction or simply pay the full sum.

The House is considering a bill to raise the cap on overtime for Secret Service agents, a third of whom had already hit the limit as of August. The agency, in a statement, said the bill would be a "tremendous lift to employee morale."

The bill has not yet been voted on in the Senate.

Homeland Security is not powerless to address the situation for FEMA, said attorney Jacob Statman, who represents federal workers.

While the agency can't waive the pay cap, a different law grants it the discretion to waive the requirement that a particular employee pay back the excessive compensation, if the employee requests the waiver and the government determines that collection "would be against equity and good conscience and not in the best interests of the United States."

Asked about that prospect, the Office of Personnel Management said that "The head of each agency has authority to administer the overpayment waiver authority" under the statute.