Government workers and retirees can save as much as $1,000 in premiums and out-of-pocket costs next year depending on which health plan they choose during the open season that begins Nov. 9.

Comparison shopping is particularly important this year because of changes in benefits, increased deductibles in some plans, and the big jump in premiums -- an average of 31 percent -- coming next year.

Although premiums charged by some of the major health plans are going up, many plans in the federal health program -- especially health maintenance organizations -- are holding the line or will charge less next year than they did in 1987. The trick is figuring which plan is best for you and your family.

Uncle Sam will help workers up to a point. Federal agencies will distribute brochures and booklets showing premiums and major benefits. But it's up to workers to make the decision.

Several quasi-government and outside sources are providing free insurance shopping help. Here are some suggestions:At 1 p.m. tomorrow, the Maryland Federation of Chapters, National Association of Retired Federal Employees, will begin a series of seminars on how to pick the best insurance plan. NARFE Secretary Gordon Brown, one of the nation's top experts on the federal health program, will conduct the series of statewide seminars, with backup from other health experts. Tomorrow's meeting is at the Urbana Fire House.NARFE will hold a seminar at 7 p.m. Nov. 17 at the Bowie Public Library; 1 p.m. Nov. 19 at the Oxon Hill Public Library; 1 p.m. Nov. 20 at the Zion United Church of Christ, and 1 p.m. Nov. 23 at Northwood High School. For information on the NARFE meetings call Martin Wish at 649-1979.A special health fair will be held at 10 a.m. Dec. 4 at the Goddard Space Flight Center in Greenbelt.The Nov. 3 and Nov. 10 issues of The Washington Post's Health Section will focus on health insurance plans for federal and postal workers, and retirees, in the Washington area.Rep. Steny Hoyer (D-Md.) will sponsor a seminar on the federal health insurance program and the new federal retirement program at 7:30 p.m. Nov. 9 at Eleanor Roosevelt High School in Greenbelt. Walton Francis of The Washington Consumer Checkbook magazine will answer questions about health plans.Rep. Thomas McMillen (D-Md.) will sponsor a health plan seminar in his district Nov. 12. For time and location call his office at 225-8090.Montgomery County residents will get health plan advice at a meeting at 7:30 p.m. Nov. 16 at the Einstein High School in Kensington. Rep. Constance Morella (R-Md.) is sponsoring the session, which will include experts from the Office of Personnel Management, Checkbook Magazine and NARFE.Virginians will get health insurance help at a Nov. 14 session at the Luther Jackson Intermediate School in Falls Church. Rep. Frank R. Wolf (R-Va.) is sponsoring the program, which begins at 9:30 a.m. Meetings

Office of Personnel Management's Leonard R. Klein will talk about simplified federal hiring procedures at the Nov. 12 luncheon of the International Personnel Management Association. The session is at the George Washington University Club. Call Joanne Jones at 696-4921.