Health premiums of federal workers and retirees will, in most cases, go up next year. The new rates and benefits will be announced shortly. There will be an open season in November and December when people can shop for the best insurance deal for 1991.

Currently, workers and retirees in the same plan (there are 26 available to federal employees here) pay the same premiums and get the same coverage. The government picks up about 60 percent of the average premium.

Many younger workers feel they subsidize retirees. Many retirees think they would be better off in plans that don't offer benefits that cover young families.

Two weeks ago in this space, a Blue Cross-Blue Shield official said that retirees on average have higher medical bills than younger workers. Many retirees disagree. Today's lead letter is from a man who says he believes retirees with Medicare are subsidizing retirees who don't have it. A second Monday Morning Quarterback says the answer is two plans: One for retirees and one for workers:

"The Blue Cross-Blue Shield official quoted in your Aug. 27 column addressed the issues of subsidies and risk-sharing in the federal health program. He stated . . . the purpose of insurance is to have the large majority subsidize the small minority. This . . . is based on the concept that all the insured under a plan have similar risks, and there is no way of telling beforehand the level of medical cost each person will actually incur.

"However in the federal health program . . . Medicare pays approximately 70 percent of the costs of retirees who have it. This leaves only a small balance to be paid by the federal health program. Notwithstanding this small possible risk, these retirees with Medicare still have to pay exactly the same premiums as the retirees without Medicare and active workers too.

"It is the retiree without Medicare who now gets the biggest bang for the premium buck. This retiree is found mainly in the age 55-to-64 group and presents the greatest risk factor because of age and the fact that the federal health program as his primary insurer pays most of his medical costs. Most retirees in this age group have gone on to a new career and are generally in a good position to pay a larger share of the risks, but instead end up being subsidized by the retiree with Medicare.

"Retirees with Medicare should be removed into a separate Medicare supplemental plan . . . . This certainly is the simplest and most equitable way of handling the problem." MORRIS SCHOLL Silver Spring

"I don't care what figures Blue Cross-Blue Shield comes up with. You cannot convince me that young couples with children and all the attendant medical and dental expenses they incur cost 'less' to a health plan than retirees.

"Retirees 60 and older don't need maternity benefits. There should be two health plans. One for working people. The other for the special health needs (and excluding unneeded items like maternity benefits) of retirees." R.N. Fairfax