Government workers anxious to get a health plan with dental benefits and retirees shopping for the best 1983 medical protection need to be especially careful during the insurance shopping season that ends Dec. 23.

Premiums in the federal health program -- which covers nearly half the people in the Washington area -- will go up an average of 24 percent next month.

The increases mean that next year the 410,000 U.S. workers and retirees here will wind up paying anywhere from $300 to $1,600 for health insurance plans that offer a wide array of benefits.

Although the government was supposed to supply workers with information at the office -- and to retirees at home -- many people complain that they still have not been given premium and benefit comparison charts, and are therefore still in the dark about what plan to pick for 1983.

In yesterday's column we listed a a number of plans rated highly by the Washington Consumers CHECKBOOK for maternity coverage, mental health benefits, catastrophic illness and so-called overall best buys.

Today's column also has a chart showing the plans available to Washington area feds and comparing 1983 premiums with those for this year.

The point to keep is mind is that there is no single "best" health plan. Premiums vary, as does coverage.

You should focus on plans that look good, and get their brochures (either at your agency health insurance office or by calling the plan direct) and see which offers the best coverage for your needs for the least amount of money.

Today, CHECKBOOK's editors have some suggested "best buys" if you are looking for dental health coverage, and also for retirees seeking a health plan that will meet their likely 1983 needs at the lowest price. Here goes:

Dental Benefits: Postmasters high option plan; Mail Handlers high option; National Federation of Federal Employes; National Treasury Employes Union, and National Association of Government Employes.

One thing to remember is that you must be a member of the Postmasters plan for three years to get full dental benefits.

Two other plans to consider are the Aetna high option and Blue Cross-Blue Shield standard option, but they are less inclusive than the others.

Typically plans that offer dental benefits cost more. But if you want them and need them, those plans can be a better bargain for you and your family than a plan with lower premiums that excludes dental care.

Retirees: There are 71,000 federal retirees in this area. Many of them have special health-care needs. Typically they can expect to have medical and doctor bills that are two to three times higher than those of younger workers.

Annuitants who have Medicare coverage (and who are 65) can get by nicely in most cases with lower premium plans. CHECKBOOK recommends those retirees take at look at the Aetna low option, Blue Cross-Blue Shield standard option, Government Employes Hospital Association (GEHA), Postmasters low option, National Association of Government Employes and National Treasury Employes Union plans.

Retirees who do not have Medicare or who are not yet eligible for it because they are under 65 should consider GEHA, Blue Cross-Blue Shield standard option, National Alliance of Postal and Federal Employes, National Federation of Federal Employes, National Association of Government Employes and various HMOs (health maintenance organizations).

Retirees should pay special attention to plans that pay all or a portion of presscription drugs, and also have good benefits for home nursing care.

Health Plan Seminars:: Rep. Stan Parris (R-Va.) is sponsoring one this evening, 7 p.m. at the Robert E. Lee High School in Springfield. Call 225-4076 for details . . . Rep. Frank Wolf (R-Va.) and the National Association of Retired Federal Employes will have a seminar tomorrow from 9:30 a.m. to 12:30 p.m. at the McLean Community Center. Call 734-1500 for information.