A federal judge ruled Monday that about 25,000 federal employees who worked without pay during the 2013 partial government shutdown are eligible for partial back pay even though they later were fully paid for that time.

The case involves employees who were told to stay on the job, typically because of the national security or public safety nature of their work, while others were furloughed when political leaders hit a deadlock and agency spending authority lapsed at the start of the government’s fiscal year Oct. 1.

The partial shutdown lasted two weeks, with both those who stayed on the job and those who were furloughed later paid in full, most commonly with the following paycheck. There were separate furloughs in 2013 related to the “sequestration” budget caps imposed that year; those furloughed for that reason were not paid later.

At issue in Martin v. U.S. before the U.S. Court of Federal Claims was whether, regardless of the funding lapse, the Fair Labor Standards Act obligated the government to pay the minimum wage — as well as overtime pay, if applicable — to those it kept on the job during the October shutdown.

The government argued that it could not pay anyone during that period because of the Anti-Deficiency Act, which bars federal officials from paying out money if Congress hasn’t appropriated it.

Chief Judge Patricia Elaine Campbell-Smith agreed with the employees, though, that regardless of the anti-deficiency law, the FLSA obligated the government to examine whether it was required to pay employees who continued to work — and that by failing to do that it violated the FLSA. She found it irrelevant that they later were paid for that time.

After an earlier ruling in favor of the plaintiffs, notices had been sent to about 300,000 federal employees stating that they may be eligible to join the suit, which originally was brought by five U.S. Bureau of Prisons employees. More than 25,000 joined the case.

Tuesday’s award covers time that employees who were covered by the FLSA (“non-exempt” employees) spent on the job between Oct. 1 and Oct. 5, 2013, the days that were unpaid in the pay distributions covering the pertinent two-week pay period. It entitles them to pay at the minimum wage rate — $7.25 an hour — for those hours, plus an amount equal to any overtime pay they earned.

The judge ordered the government and the plaintiffs to calculate amounts due and report back to her by April 7.

There is no estimate of the potential value of the award, said Heidi Burakiewicz, a partner with Mehri & Skalet, the Washington law firm representing the employees. The award applies only to those who signed on to the class action, she added, and “it’s too late, unfortunately, for anyone else to get into the class.”

Burakiewicz said that many of the affected employees work in only moderately paying occupations such as law enforcement, firefighting and prison guard. “They didn’t know how long the shutdown was going to last or how long they had to go without a paycheck. There were a lot of employees who depleted their savings” and had to choose which bills to pay and incurred late-payment penalties, she said.

“It’s not acceptable to treat an employee that way. It’s especially not acceptable for the federal government to treat its public safety employees that way,” she said.

Correction: An earlier version of this story provided inaccurate information about the number of employees who received notices of eligibility. It has been corrected.