Federal employee insurance payments aren’t going up much, but when your basic pay is frozen, any increase can be too much.

Next year, health insurance premiums in the Federal Employees Health Benefits Program (FEHBP) will rise by an average 3.4 percent, with no major benefit ­changes, the Office of Personnel Management announced Thursday.

That’s down from the 3.8 percent increase this year and less than half of the 7.4 percent jump in 2010.

But with the freeze on basic federal pay rates, now expected to go through the spring, the modest increase is not welcome.

Because of the freeze, “Congress and the administration have decided to turn the federal workforce into a ‘fixed income’ population that simply cannot afford another cent toward already-inflated FEHBP premiums,” said J. David Cox Sr., president of the American Federation of Government Employees (AFGE).

“Now federal employees are facing the prospect of an extension of the pay freeze through April 2013,” Cox said as he called for a moratorium on premium hikes. “How can they be expected to afford another increase in FEHBP rates while their salaries don’t increase — it’s the same as a pay cut.”

Walt Francis, a health economist, had a different view. Of course, he is not a federal employee and doesn’t represent them. He said that “the 3.4 percent average increase is great news for feds in this era of pay freezes.”

It’s not great news to Colleen M. Kelley, president of the National Treasury Employees Union (NTEU).

“Any increase is hard for federal employees given the freeze on federal pay,” she said. “NTEU is committed to working to make the proposed 0.5 percent pay raise for the federal workforce retroactive to January and to increase pay raises in the following years.”

In dollar terms, the premium increases will result in an average of $6.39 more per bi­weekly paycheck for family coverage in 2013 and $2.75 for just the employee. Fees for health maintenance organizations will go up more, an average of 5.3 percent. Fee-for-service plans’ average increase will be 3.0 percent.

“I am pleased that we were able to keep the average increase low again this year,” said OPM Director John Berry. “Once again, we successfully used our market leverage and previous years’ experience to negotiate the lowest possible premium rates without sacrificing benefits.”

Francis, the primary author of Checkbook’s Guide to Health Plans for Federal Employees, credited “OPM leadership, improved plan management, good employee and retiree decisions, and plain good luck on prescription drug prices” for the comparatively low premium increases.

But all those things and Uncle Sam’s leverage apparently aren’t strong enough to drop premiums low enough so that all federal employees can afford insurance through FEHBP.

“The unaffordability of health insurance through FEHBP is a huge problem,” said Jacqueline Simon, AFGE’s public policy director. “We estimate that at least 250,000 federal employees who are eligible for FEHBP coverage are uninsured because they cannot afford the premiums, and the premium increases that have occurred during the two-years-and-counting pay freeze have probably added to that number.”

Without commenting directly on the 250,000 estimate, an agency representative said OPM is “aware that there are some eligible employees and annuitants who do not enroll in the FEHB Program,” sometimes because they have alternative coverage. “We work hard to keep rates as reasonable as possible and provide a broad choice of plans with a range of options and premiums.”

On his congressional salary, Rep. Jesse L. Jackson Jr. probably can afford the premiums. But although members of Congress, like other federal employees, are covered by FEHBP, the Illinois Democrat has to sell his District home to pay for his medical bills, according to his congressional office. Jackson was on medical leave for depression for almost three months starting in June and received in-patient treatment at three facilities during that time.

“Like millions of Americans, Congressman Jackson and Mrs. Jackson are grappling with soaring health-care costs and are selling their residence to help defray costs of their obligations,” said Rick Bryant, Jackson’s spokesman. Bryant said he had no information on the details of Jackson’s insurance coverage.

FEHBP plans have limits on the amount enrollees have to pay out of pocket, but those limits might not apply if patients seek care out of their plans’ networks.

Simon said one hole in coverage generally for federal employees, which could result in high out-of-pocket payments, is the lack of disability insurance. In some cases, she said, workers who are “too ill to work but not disabled enough to qualify for SSI,” the government’s Supplemental Security Income program, might encounter high personal health-care expenses.

Open season, the period when federal employees can change health plans, runs from Nov. 12 through Dec. 10.

Previous columns by Joe Davidson are available at wapo.st/JoeDavidson.