The 447,000 federal workers and retirees here who buy health insurance through Uncle Sam may be frozen into their present plan at least until spring even though premiums for most plans will jump in January from 5 percent to 50 percent (for one small plan). That means many workers will pay more and get less next year, thanks to benefit cutbacks, but won't be able to switch plans for a while.

Office of Personnel Management -- which has been in a long-running legal battle with federal unions because it wants them to trim 1982 benefits -- says it is probably too late to hold an "open season" enrollment period this year. OPM doesn't know when federal and postal workers and retirees will get a chance to go shopping for lower premiums or switch coverage in the program that covers 9.2 million people.

Open season (the period when workers and retirees can switch health plans or coverage) was originally scheduled to begin next week. But the battles over OPM attempts to bar abortions from the 1982 health program and force some plans to make even deeper cuts in other benefits have consumed so much time that it has upset the government timetable for printing 1982 insurance brochures.

OPM will appeal a Friday ruling by U.S. District Court Judge Aubrey E. Robinson Jr., who said OPM Director Donald Devine acted illegally in late September when he told health plans to make additional cuts in 1982 benefits on top of earlier OPM-directed cuts they had made. The American Federation of Government Employees, joined by the National Federation of Federal Employees, went into court arguing that OPM could not order further budget cuts.

OPM Director Devine, in unusually strong language, charged that Judge Robinson's decision against him "usurped a fundamental authority conferred by the Constitution on the legislature." Devine said OPM will appeal the ruling which, he said, prevents OPM from reducing health insurance premiums and benefits "in order to obey budget constraints ordered by Congress."

All this means you are probably stuck with your present health insurance plan for some time to come -- no matter how much you hate it when you see the new rates and benefits schedule for 1982.