A new federal law takes effect this month that may save you thousands of dollars in health-insurance bills. It can come to your rescue if you're in danger of losing employe-health insurance.

Who will be helped? Spouses and children who depend on the breadwinner's coverage to pay their medical bills. Many employes who get laid off. Early retirees and their families. Widows, widowers and the newly divorced. Young people who get too old for coverage under their parents' plan.

If you fall under the law's protection, you'll be able continue your employe group-health insurance for as many as three years, at your own expense. Group coverage isn't cheap but it costs less -- and probably gives you better coverage -- than if you had to buy a policy on the open market. No medical exam is needed. You'll pay the plan's group rate (usually in the area of $100 or more per month) plus 2 percent.

Losing health insurance has been overwhelmingly a problem for women and children, although men are certainly not exempt. In most states, when a man died or divorced, his nonworking widow or ex-wife suddenly lost the benefit of his group coverage. If he retired on Medicare but she was under 65, she was also stuck. Often, she couldn't afford to buy her own policy; if she had health problems, she might not even be insurable.

Laid-off workers often go without health insurance between jobs or if they retire before 65. A few states require employers to continue their group-health policies for various periods of time. But the vast majority who lost coverage have had to take their chances.

For many workers, this unhappy situation will not change. You are not protected by the new law if you work for a company with fewer than 20 employes; if you already have lost your group-health insurance; if you lose it before the law's effective date for your particular health plan; if you're employed by the District of Columbia; or if you're covered by a church plan. Federal workers also are not covered, although they have a partial insurance-continuation plan of their own.

For most of the workers who are covered, the law will phase in gradually during the next 12 months. Your protection begins at the start of your official "plan year," which could be anytime between July 1, 1986, and June l987. If you're in a union-negotiated plan, your group-health coverage may not be safe until the contract expires, which could be two or more years away.

Many technical questions about the new law have yet to be resolved, Alice Quinlan of the Older Women's League told my associate, Virginia Wilson. But in general, here's what it requires:

If your spouse dies after the law becomes effective for your particular health plan and you're covered by his or her family policy: You and your children can continue your group coverage, at your own expense, for up to three years. The employer is supposed to notify the health plan about the death (check to see that it's done!). When you're offered coverage, you have 60 days to accept. If you delay, you'll be dropped from the plan with no appeal.

If you're covered by your spouse's health plan and become separated or divorced, you can continue your coverage for up to three years, at your expense. Typically, your children still will be insured under his continuing plan. But if not, you may buy group coverage for them, too. (The law does not restore group-health insurance to people who already have lost coverage after divorce.)

Warning: To buy this coverage, you MUST -- yourself -- notify the health plan about your change in marital status. The plan should offer you coverage within two weeks. You then have 60 days to accept. If you don't follow through on this, you will lose your eligibility.

If your spouse retires and you're too young for Medicare, you can pay for group coverage for up to three years.

If your hours are cut or you lose your job -- for any reason other than "gross misconduct" -- you and your family can carry your group coverage for up to 18 months.

When your child becomes ineligible for your health plan, the child may buy the same insurance for up to three years at group rates. Be sure to alert the plan soon before the child is due to go off the rolls.

Your coverage ends if: you fail to pay the premium; become eligible for coverage elsewhere (through another employer, remarriage or Medicare); the company drops its group policy; or your alloted time runs out.

For a free brochure on your rights under this new law, send a self-addressed, stamped envelope to The Older Women's League, Insurance Continuation, 1325 G St. NW, Washington D.C. 20005. Expect to wait for a couple of weeks, because OWL is being swamped with requests.