The typical federal worker or retiree can save about $1,000 next year if he or she picks the right health insurance plan during the open enrollment period that begins today.

By Dec. 6, several million current and former feds -- senators, typists, astronauts, CIA agents and diplomats -- must pick their 1986 health plan.

More than 10 million persons, including half the population of the Washington area, are covered by the program, the country's biggest "company" plan.

There are several hundred plans, and people in the Washington area are eligible for about 20 of them. There is no one best plan for everyone. Price and coverage vary greatly in the plans offered. They range from such nationwide giants as Blue Cross-Blue Shield to union-backed plans and home town health maintenance organizations.

Picking the best plan is never easy. But comparison shopping is especially important now because so many of the plans are cutting premiums. The average reduction is 6 percent, but some are cutting premiums as much as 40 percent.

On Sept. 4 this column listed the new premiums for federal workers. On Sept. 8 we listed the premiums for retirees. But premiums don't tell the whole story. In addition to premiums, one must figure likely out-of-pocket costs not covered by insurance.

Today we are listing the "best buys" for the typical employe, as rated by Washington Consumers Checkbook magazine. Checkbook's ratings take into account premiums and likely expenses for a typical family of four.

In later columns we will list "best buys" for retirees, for single persons and for people expecting heavy medical bills.

In addition to the brief best-buy listings here, Checkbook, which goes on sale this week at newsstands, gives a detailed breakdown of plans by cost, coverage and service record.

Here is the listing of "best buys" for a typical family of four expecting average medical expenses next year. Bear in mind that the dollar figures listed beside each plan include not only premiums (or fees for joining) but also likely out-of-pocket medical costs for next year. Here are the best buys:

Special Agents Mutual Benefit Association plan; costs -- premiums and out-of-pocket costs -- for a typical family of four next year are estimated at $1,430. Blue Cross-Blue Shield standard option; cost: $1,460. Government Employees Hospital Association, $1,470. HealthPlus standard option, $1,480. Columbia Health Plan, $1,500. HealthPlus high option, $1,510. Aetna standard option, $1,530. Government Employees Benefit Association low option, $1,560. M.D. IPA plan, $1,560. Network plan, $1,570. Foreign Service plan, $1,600. Mail Handlers high option, $1,620. Mail Handlers standard low option, $1,640. CapitalCare, $1,640. National Association of Letter Carriers, $1,720. Postal Supervisors, $1,760. American Federation of Government Employees high option preferred, $1,780. American Postal Workers Union, $1,780. Postmasters standard plan, $1,810.