The 1982 health insurance hunting season for 460,000 federal workers and retirees here will be held from May 3 to May 28.

Coverage for active duty feds who switch health plans will begin July 11. Retirees who change insurance plans will be covered by their new program beginning July 1.

Office of Personnel Management yesterday officially announced the "no strings" open season. As reported here last week, OPM said it tentatively plans to hold another open season--to run from Nov. 22 to Dec. 10--so that workers and retirees can select health plans for 1983.

Workers who switch health plans during the May open season will not have to pay any sort of transfer fee. Nor will preexisting medical conditions be excluded for people who move into another health plan. OPM earlier had considered imposing those restrictions on people who switched.

Individuals who have paid all or part of the deductible in their current health plan will have the amount paid credited to the deductible of their new health plan. A deductible is the amount a subscriber must pay each calendar year before his or her plan begins paying benefits.

There was no open season last year. OPM was tied up in court most of 1981 trying to impose government-ordered cutbacks in benefits paid for such things as abortions, mental health treatment and alcoholism. The government pays the lion's share of premiums and OPM said it wanted to hold down 1982 costs.

Because there was no open season, nearly a million Washington area residents--from cabinet officers to congressmen, clerks and their families--were stuck in their health plans. Premiums jumped an average of 30 percent in January.

In addition to health plan brochures (supposed to be available at most agency insurance offices), OPM soon will distribute open season instructions and a booklet comparing rates and coverage offered by the 120-plus plans in the program.