More than 100 House members have asked their conferees on a proposed Medicare catastrophic illness insurance plan to make sure that retired state, federal and military personnel aren't socked with super-high premiums for coverage most of them already have.

Senate-House conferees early next year are expected to approve the expanded health care coverage for retirees who are 65 and older. Under the House version of the bill the typical government retiree, who already has catastrophic medical care coverage as part of the federal insurance program, would be hit with added Medicare premiums of $530 next year, while the premium rise for nonfederal retirees would be only about $110.

Although the catastrophic illness coverage is badly needed by many older Americans who don't have adequate insurance, it would be duplicative, and five times as costly, for federal retirees.

The House bill would base premiums on taxable income. That would be a break for persons whose primary income comes from largely untaxed Social Security benefits. But it would mean higher premiums for government and private-sector retirees whose primary income is from fully taxed pensions.

Because of objections from postal and federal unions, and the National Association of Retired Federal Employees, the Senate tailored its bill to adjust income-based premiums so that government retirees wouldn't get higher bills for duplicative coverage.

The bipartisan letter to conferees -- signed by nearly one-fifth of the House -- was generated by Virginia Republican Reps. Frank R. Wolf and Stan Parris; Maryland Democratic Reps. Steny H. Hoyer and Tom McMillen, and Republican Rep. Constance A. Morella.Job Mart

General Services Administration wants a personnel staffing specialist, Grades 11 or 12. Call Mary Ann Robinson at 566-0370.

Retirement Countdown

Federal and postal employes have 10 working days left to select a pension plan. Federal workers hired prior to 1984 have two choices. They can stay in the Civil Service Retirement System or go into the new Federal Employees Retirement System. Dec. 31 is the deadline for deciding.

Although pension experts say FERS is the best bet for 40 percent of the work force, only about 3 percent have signed up. Those who join FERS can't switch back to the old plan. Workers who decide to stick with the CSRS system will be asked to sign a form stating that they had the option to join FERS and declined.

GEICO Awards

Bernard Posner, a Silver Spring retiree from the President's Committee on Employment of the Handicapped, has been named one of the winners of this year's public service awards, sponsored by the Government Employees Insurance Corp. He was honored for volunteer work with the mentally ill. The awards are made each year to outstanding workers and retirees in the fields of alcoholism, fire prevention, physical rehabilitation and traffic safety. Other winners of the award, which includes a $2,500 check, are John L. DeSmet, Veterans Administration; Kenneth Boyd-Robertson, U.S. Postal Service; Perry Tillman, Agriculture, and Rebecca C. Buchan, Air Force.