Dear Savvy Senior,

My wife and I are approaching 65, but I’m still working and have good health coverage through my employer. Do we need to enroll in Medicare at this point?

Almost 65

Dear Almost,

If you or your spouse is still working past age 65 and have health insurance through your job, you may be able to delay enrolling in Medicare without a late enrollment penalty. However, the rules depend largely on the size of your employer.

First, a quick refresher: Remember that original Medicare has two parts. Part A, which covers hospital care and is premium-free for most people. And Part B, which covers doctor visits, lab tests, and outpatient care and has a monthly premium of $202.90 in 2026. Higher-income individuals (over $109,000) and couples (over $218,000) pay more.

If you’re already receiving Social Security, you’ll automatically be enrolled in Parts A and B when you turn 65, and your Medicare card will arrive in the mail. It will include instructions on how to return it if you have employer coverage that allows you to delay Part B.

If you’re still working

Start by talking with your benefits manager or HR department to understand how your employer insurance works with Medicare. In most cases, it makes sense to enroll in Part A since it’s free. However, if you contribute to a Health Savings Account, enrolling in Part A will stop those contributions.

Whether you should enroll in Part B usually depends on your employer’s size.

Small employer

If your employer has fewer than 20 employees, Medicare becomes your primary insurance. In this case, you should enroll in Part B during your Initial Enrollment Period, which lasts seven months: the three months before your 65th birthday, your birthday month, and the three months after.

If you aren’t receiving Social Security, you’ll need to apply for Medicare. You can do this online at ssa.gov/medicare/sign-up, by phone at 800-772-1213, or in person at your local Social Security office.

If you miss your Initial Enrollment Period, you’ll need to wait for the General Enrollment Period, which runs Jan. 1 through March 31. Coverage begins the first day of the month after you enroll, but a 10 percent penalty is added to your Part B premium for each full year you waited. Signing up on time helps you avoid both coverage gaps and added costs.

Large employer

If your employer has 20 or more employees, your group health plan remains your primary insurance while you’re actively working. In this case, you generally don’t need to enroll in Part B at 65 if your coverage is adequate. If you do enroll, Medicare will serve as secondary coverage.

Once your employment or employer coverage ends, you’ll have an eight-month Special Enrollment Period to sign up for Part B without penalty.

Check drug coverage

You should also review your prescription drug coverage. Ask your benefits manager if your employer’s plan is considered “creditable.” If it is, you don’t need to enroll in a Medicare Part D plan. If it isn’t, you should sign up for Part D during your Initial Enrollment Period to avoid a penalty – typically 1 percent of the national average premium for each month you delay.

You can compare Part D plans at medicare.gov/plan-compare.

Need help?

For free guidance, contact your State Health Insurance Assistance Program at 877-839-2675 or shiphelp.org. You can also call the Medicare Rights Center helpline at 800-333-4114.

Navigating Medicare while you’re still working can be confusing, but a quick check with your employer and a clear understanding of the rules can help you avoid costly mistakes. Taking the time to get it right now will ensure you have the coverage you need, without unnecessary penalties down the road.

Journalist and senior advocate Jim Miller is the creator of Savvy Senior, a weekly information column devoted to older adults that appears in more than 250 U.S. newspapers and magazines. He is also the author of The Savvy Senior: The Ultimate Guide to Health, Family and Finances for Senior Citizens (Hyperion) and is frequently featured in major media outlets, including Time, USA Today, The New York Times, CNBC and CNN.