Many federal workers and retirees who are enrolled in large health plans will get a jolt next week when the government announces the premium rate structure for 1988.

Although not all plans will increase premiums, insiders predict that some of the bigger, more popular health plans will be raising premiums 20 percent or more. That will take a bite out of paychecks of workers -- who are expecting a pay raise next year of between 2 and 3 percent -- and of retirees who are tentatively due a 3.7 percent cost of living raise.

Premiums this year went up an average of 14 percent. In 1986, premiums, on the average, dropped about 6 percent. There are more than 200 plans in the federal health program, which is the country's largest company health plan. It covers about 12 million active and retired government workers and family members, and helps pay medical and dental bills for more than half of the population of the Washington area.

Federal workers on the average pay about 39 percent of total health premiums. Postal workers, who bargain separately on wages and fringe benefits, pay about 25 percent of their average premiums.

Premiums now range from less than $300 a year in some plans to nearly $2,000 in more comprehensive programs. The government will have a health insurance open season later this year when employes and retirees will pick the coverage they want for 1988.

If the big premium increases predicted come to pass, hundreds of thousands may switch over.

Paycheck Issues

Federal employe unions are getting good results from stepped-up campaigns to win back pay for employes who lost money because they were discharged in error or their jobs were misclassified:

The American Federation of Government Employees says that Border Patrol employe Robert J. Marren will be getting about $25,000 in back pay as the result of a Merit Systems Protection Board ruling against the Immigration and Naturalization Service. Marren, who is also a regional vice president of the union's border patrol council, was fired then restored to his job. But the government refused to give him full back pay, and the union took the case to the board. The appeals agency threatened to stop salaries of key INS officials unless they give Marren his full back pay or satisfactorily explain why the money was withheld.

The National Federation of Federal Employees won $14,000 in back overtime pay for Walter Sabey, a government civilian test pilot in New Jersey. The government had contended that certain test pilots, at the Grade 12 and 13 levels, were exempt from overtime regulations. The U.S. Court of Claims upheld the overtime claim that will give some pilots as much as nine years of back overtime pay from 1975 to 1984.

The Federal Labor Relations Board has agreed that two Treasury Department units -- the Internal Revenue Service and U.S. Customs Service -- must negotiate with the National Treasury Employees Union on the issue of hand-delivery of paychecks. As part of a cost-cutting program, many agencies require employes to have paychecks sent directly to banks or credit unions. They argued that the paycheck distribution method isn't subject to labor-management negotiations. But a recent U.S. Court of Appeals decision said the issue is negotiable.