The Office of Personnel Management on Monday announced that it would reduce call-center hours and halt overtime for employees who process federal-retiree pensions as a result of the government-wide spending cuts that took effect last month.

The OPM has not indicated when the overtime suspension, which took effect on Sunday, would end.

The agency in recent years has struggled with a backlog of unresolved pension cases, although its numbers have improved steadily since January 2012, when former director John Berry hired more workers and increased overtime to address the issue.

At that point, the number of unprocessed claims stood at 61,000. By March of this year, the number had dropped to about 37,000.

The OPM said in a statement on Monday that “retirees should expect an increase in the time required to process their claims or respond to inquiries” as a result of the overtime suspension and reduced hours.

The agency’s call center was previously open from 7:30 a.m. until 7:45 p.m., but the new closing time will be 5 p.m.