You don't have to sign up for Medicare at 65, but waiting can cost you money for the rest of your life

Medicare enrollment is not automatic at 65. You have to sign up yourself, either before you turn 65 or during your initial enrollment period. If you miss that window and don't have other coverage, you will pay a permanent penalty on your Part B and Part D premiums — even after you finally enroll. The penalty stays with you for as long as you have Medicare.

The one exception: if you are still working and covered by your employer's health plan, you may be able to delay enrollment without penalty. But you have to meet specific conditions, and you still need to sign up eventually.

Key Takeaways

  • Your initial enrollment period runs for seven months: three months before the month you turn 65, the month you turn 65, and three months after.
  • If you miss this window and have no other health coverage, you will pay a 10 percent penalty on Part B premiums and a 1 percent penalty on Part D premiums for as long as you have Medicare.
  • You can delay enrollment without penalty only if you have coverage through your current employer or your spouse's current employer, and you must enroll within eight months of losing that coverage.
  • You sign up through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.

What happens if you miss your enrollment important date

If you do not sign up during your initial enrollment period and you do not have other health coverage, Medicare will charge you a late enrollment penalty. This penalty is permanent — it does not go away after a few years.

The Part B penalty is 10 percent of the standard premium for each full 12-month period you were not enrolled. If you wait two years to sign up, you pay a 20 percent penalty on top of the regular premium for the rest of your life. The Part D (prescription drug) penalty works the same way at 1 percent per year.

These penalties add up. A person who waits three years to enroll could pay an extra $50 to $100 per month in premiums, depending on the year and the plan. Over a 20-year retirement, that is thousands of dollars in extra cost.

When you can delay enrollment without a penalty

You can postpone signing up for Part B without penalty if you have creditable coverage through your job or your spouse's job. Creditable coverage means health insurance that is at least as good as Medicare Part B. Most employer plans may have access to.

You must still enroll in Part A (hospital insurance) at 65 if you are receiving Social Security benefits, because Part A is free for most people. But you can wait on Part B and Part D.

Once you leave your job or lose your employer coverage, you have eight months to sign up for Part B and Part D without penalty. This is called your special enrollment period. If you miss this eight-month window, the late penalty applies.

Before you decide to delay, ask your employer's benefits office in writing whether your plan is creditable coverage. Get the answer in writing so you have proof if Medicare questions your enrollment later.

Your initial enrollment period: the seven-month window

Your initial enrollment period is seven months long. It starts three months before the month you turn 65 and ends three months after the month you turn 65.

If you turn 65 in June, your enrollment period runs from March through September. You can sign up any time during those seven months. Medicare coverage can start as early as the first day of the month you turn 65, depending on when you enroll.

If you sign up in the three months before you turn 65, your coverage usually starts the month you turn 65. If you sign up in the month you turn 65 or later, there may be a one-month delay. The exact date depends on which day of the month you enroll, so check with Medicare when you sign up.

How to sign up for Medicare

You have three ways to enroll: online, by phone, or in person.

Online: Go to Medicare.gov and click "Sign Up for Medicare." You will need your Social Security number, date of birth, and contact information. You can complete the process in one sitting or save it and come back later.

By phone: Call 1-800-MEDICARE (1-800-633-4227). Representatives are available Monday through Friday, 8 a.m. to 8 p.m. Eastern time. They can answer questions about your coverage options and help you enroll over the phone.

In person: Visit your local Social Security office. You can find the nearest office at ssa.gov/locator. Bring your Social Security card, birth certificate, and proof of citizenship or legal residency. No appointment is needed, but wait times vary.

What you need to decide when you enroll

When you sign up, you will choose between Original Medicare (Part A and Part B) and Medicare Advantage (Part C). You will also choose whether to enroll in Part D (prescription drug coverage) or a separate drug plan through your Medicare Advantage plan.

Original Medicare covers hospital stays, doctor visits, and some outpatient care. You pay a monthly premium for Part B, a deductible, and coinsurance when you use services. You can see any doctor who accepts Medicare.

Medicare Advantage is an alternative to Original Medicare offered by private insurance companies. It usually includes prescription drug coverage and may cover dental, vision, or hearing. You typically pay a lower or zero monthly premium, but you must use doctors and hospitals in the plan's network.

You do not have to choose right now. If you are unsure, you can enroll in Original Medicare during your initial enrollment period and switch to Medicare Advantage later during the annual open enrollment period (October 15 to December 7 each year).

Special situations: working past 65 or losing coverage

If you keep working past 65 and stay on your employer's health plan, you can delay Part B and Part D enrollment. But you must sign up within eight months of leaving your job or losing coverage, or you will face late penalties.

If you are covered by your spouse's employer plan and your spouse is still working, the same rule applies. You have eight months after your spouse retires or you lose coverage to enroll without penalty.

If you are on COBRA (temporary coverage after leaving a job), that counts as creditable coverage. You can delay Part B and Part D while you are on COBRA, but enroll within eight months of COBRA ending.

Frequently Asked Questions

What if I turn 65 but I'm not ready to retire?

You can still enroll in Medicare while working. If you have employer coverage, you can delay Part B and Part D without penalty. Part A is free for most people at 65, so there is no harm in enrolling in it. You do not have to use Medicare right away — it sits in the background until you need it.

Can I sign up for Medicare after my initial enrollment period ends?

Yes, but you will pay a late penalty unless you have a may have access to reason (like current employer coverage). You can enroll during the general enrollment period from January 1 to March 31 each year, with coverage starting July 1. The penalty is permanent, so enroll as soon as you can.

Do I have to enroll in Part D if I don't take prescription drugs?

You do not have to enroll in Part D right now if you have no prescriptions. But if you enroll later, you will pay a 1 percent penalty for each month you were not enrolled. If you think you might need drugs in the future, it is cheaper to enroll now and pay zero penalty.

What happens to my employer coverage if I sign up for Medicare?

You can have both. Medicare becomes your primary insurance, and your employer plan becomes secondary. Your employer plan will coordinate benefits with Medicare. Ask your benefits office how this works with your specific plan before you enroll.

Can I change my mind after I sign up?

Yes. You have a one-time chance to change from Original Medicare to Medicare Advantage (or vice versa) during the annual open enrollment period from October 15 to December 7. You can also switch prescription drug plans during this period. Changes take effect January 1.