Health insurance premiums will go up an average of 4.8 percent next year. At the same time, federal workers are due a 3.5 percent raise and retirees anticipate a cost- of-living adjustment of about 5 percent.

Although the 1991 premium increase is the lowest in years, many people will be looking for less-expensive coverage. For most, that will mean moving from their plans' high option to its standard option, finding a new plan or trying out a low-cost health maintenance organization.

Like it or not, the 1991 insurance-hunting season opens one month from tomorrow. If you don't pick a new plan, you will be kept in the one you are enrolled in. If you are in a high option or a plan with a big premium increase, doing nothing could cost you.

During the last federal insurance open season, almost half a million people switched plans or options.

The biggest change was an involuntary one. It involved the popular (but expensive) Aetna fee-for-service plan. Aetna left the federal health program, and its 180,000 federal subscribers (most of them very old retirees) had to find new coverage for 1990. About 60 percent switched to Blue Cross-Blue Shield. Another 20 percent switched to one of the many HMOs in the federal program.

During the last open season, many subscribers wised up to the fact that they were paying thousands of dollars a year for unnecessary (in most cases) high-option coverage. Blue Cross-Blue Shield's high-option plan lost 29,000 subscribers. Its standard-option package, however, picked up 194,000 new members. Ironically, the less-costly standard option gives some dental benefits that aren't offered by the most expensive high-option plan.

GEHA, a popular fee-for- service plan, picked up 24,000 new subscribers this year. The American Postal Workers Union plan gained 10,333 new policyholders.

Many plans that lost subscribers -- the National Association of Government Employees, GEBA, Postal Supervisors, National Federation of Federal Employees and American Federation of Government Employees -- dropped out of the 1991 health program. AFGE blamed the Bush (and Reagan) administrations for its insurance problems. But, in fact, it had lost 3,000 of its 17,000 subscribers and had trouble getting an underwriter.

The National Treasury Employees Union, which lost 3,562 subscribers and now has 15,511, hopes to bounce back this year because it has slightly increased some benefits while cutting premiums for both its single and family option. Many HMOs have also held the line or actually reduced premiums and hope to pick up people who are sick of paying ever-higher high-option premiums.

Pension Option

Tomorrow at noon on WNTR radio (1050 AM), financial planners Paul Yurachek and David Cohen will talk about the tax implications of taking the lump-sum pension option and will outline who should take the popular benefit.

Mini Vacation

I'm taking a long weekend and will be back in this space the middle of next week.