Federal workers who now pay anywhere from $300 to $1,100 a year for health insurance may be shifted to a voucher system in 1984 that would give them a government check covering the entire premium -- if they selected a basic, no-frills policy.

At present, government employes pay anywhere from one-third to almost two-thirds of their premiums, depending on coverage they pick from 120 bewildering varieties offered in Uncle Sam's office health program. It covers 9.2 million people -- workers and their families.

Because of the elaborate system determining the percentage of health premiums the government pays -- the formula is based on an average of the premiums charged by six major plans in the program -- the amount varies from plan to plan, and between options offered within plans. In short, it is complicated, as witness the trauma each year when workers and retirees have to shop for insurance for the upcoming year. (The open season for the 1983 insurance plan will be held in November of this year.)

To simplify (??) things, the administration is considering some changes. One of them would be a voucher plan.

Under it, workers and retirees would get a flat dollar amount each year to be used to buy health insurance.

Ideally, an OPM official said, the voucher would cover the entire premium for a policy offering basic coverage for a worker and family. Those who wanted what he termed "Cadillac coverage" would have to pay the difference for the higher premium out of pocket.

It sounds good. But federal folks these days are suspicious that the White House and current management of OPM do not always have their best interests at heart. If OPM favors the voucher approach, some cynics think it can't be all good.

If the White House okays the OPM voucher idea, legislation to accomplish it will be introduced, but probably not until the new session of Congress. Then it will be up to union lobbyists and Congress which oversees the giant health program to determine if the system would be best for all concerned.