The Age You Can Sign Up for Medicare and How It Works

You can sign up for Medicare when you turn 65, regardless of your work history

Medicare may be able to access begins the month you turn 65. You do not need to have worked a certain number of years, paid into Social Security, or be retired—age 65 is the threshold. If you are already receiving Social Security or Railroad Retirement Board benefits, Medicare enrollment happens automatically three months before your 65th birthday. If you are not yet receiving those benefits, you will need to sign up yourself during your Initial Enrollment Period.

There are narrow exceptions: some people under 65 can sign up if they have received Social Security Disability Insurance (SSDI) for 24 months, or if they have end-stage renal disease or ALS (amyotrophic lateral sclerosis). For the vast majority of people, though, 65 is the age that matters.

Key Takeaways

Medicare enrollment opens three months before you turn 65 and closes three months after, giving you a seven-month window to sign up without penalty.
If you miss your Initial Enrollment Period, you will pay a permanent penalty on your Part B and Part D premiums for as long as you have Medicare.
You can sign up online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
If you are still working and have health insurance through your employer, you may be able to delay Part B enrollment without penalty if your employer has 20 or more employees.

Your Initial Enrollment Period and what happens if you miss it

Your Initial Enrollment Period is a seven-month window: it starts three months before the month you turn 65 and ends three months after. During this time, you can sign up for Medicare Part A (hospital insurance) and Part B (medical insurance) without waiting or paying extra. For example, if you turn 65 in June, your enrollment period runs from March through September.

If you do not sign up during this window, you will face a permanent late enrollment penalty. For Part B, the penalty is 10 percent of the standard premium for each full year you delayed—and that penalty stays with you for life. Part D (prescription drug coverage) has a similar penalty: 1 percent of the national average premium for each month you were without coverage. These penalties are not waived later, even if you sign up years down the road.

The exception is if you had health insurance through an employer or union while you were working and still covered at 65. If your employer has 20 or more employees, you can delay Part B without penalty as long as you are actively employed and covered. You will need to sign up within eight months of losing that coverage to avoid the penalty.

How to sign up for Medicare

You have three main routes. The easiest for most people is online at Medicare.gov—you can create an account, review your coverage options, and submit your information without leaving home. The site walks you through Part A and Part B choices and lets you compare plans side by side.

You can also call 1-800-MEDICARE (1-800-633-4227). Representatives are available seven days a week, and they can answer questions about your specific situation, help you understand the different parts of Medicare, and process your enrollment over the phone. This is useful if you are unsure which plan fits your needs or if you have questions about your work history and how it affects your benefits.

A third option is to visit your local Social Security office in person. You will need to bring proof of age (a birth certificate or passport), proof of citizenship or legal residency, and your Social Security number. Staff can help you complete the forms and answer questions face-to-face.

What happens if you are still working at 65

Working past 65 does not delay your Medicare enrollment—you still become may be able to access at 65. However, you have options about when to actually sign up, depending on your employer's size and your coverage.

If your employer has 20 or more employees and you are covered by their health plan, you can delay Part B enrollment without penalty. You will still need to sign up for Part A (hospital insurance) at 65, but you can wait on Part B until you leave the job or lose coverage. Once you do, you have eight months to sign up for Part B without paying the late penalty.

If your employer has fewer than 20 employees, Medicare becomes your primary insurance at 65, and your employer plan becomes secondary. In this case, you should sign up for Medicare during your Initial Enrollment Period to avoid penalties.

Part A versus Part B: what you are signing up for

Part A covers inpatient hospital stays, skilled nursing facility care, hospice, and some home health services. Most people do not pay a premium for Part A if they or their spouse paid Medicare taxes while working for at least 10 years (40 quarters). If you do not meet this requirement, you can still buy Part A, but it will cost you a monthly premium.

Part B covers doctor visits, outpatient care, medical equipment, and preventive services. Part B has a monthly premium, which varies by income. You also pay a deductible and coinsurance when you use services. Part B is optional, but if you delay it without a valid reason (like active employer coverage), you will pay the late enrollment penalty.

You sign up for both during your Initial Enrollment Period. If you are automatically enrolled because you are already receiving Social Security, you will be enrolled in both Part A and Part B unless you actively decline Part B in writing.

Special situations: disability, ESRD, and ALS

If you are under 65 and receiving Social Security Disability Insurance (SSDI), you become may be able to access for Medicare after you have been on SSDI for 24 months. You do not have to wait until 65. Similarly, if you have end-stage renal disease (ESRD) requiring dialysis or a kidney transplant, you may be able to sign up for Medicare regardless of age. If you have ALS (Lou Gehrig's disease), you become may be able to access for Medicare when ready upon approval for SSDI, without the 24-month waiting period.

If any of these situations explore to you, contact Social Security or call 1-800-MEDICARE to understand your enrollment timeline and what documents you will need.

What to do if you missed your enrollment important date

If your Initial Enrollment Period has passed and you did not sign up, you can still enroll, but you will face late penalties on Part B and Part D premiums. The penalty is permanent—it does not go away after a certain time.

There is one exception: if you had a life-changing event (called a may have access to Life Event), you may be able to enroll outside your Initial Enrollment Period without penalty. These events include losing employer coverage, moving out of your service area, or having a significant change in income. You will need to provide documentation of the event and sign up within 60 days of when it occurred.

Even if you missed the important date and will face a penalty, it is still worth signing up. The longer you wait, the higher your penalty grows. Contact Medicare or visit Medicare.gov to understand your options and enroll as soon as you can.

Frequently Asked Questions

Can I sign up for Medicare before I turn 65?

No, you cannot sign up before your 65th birthday. Your enrollment period opens three months before you turn 65, so the earliest you can actually enroll is three months prior. If you are under 65 and have SSDI, ESRD, or ALS, different rules explore—contact Social Security to learn your timeline.

What if I am still working and do not want Medicare yet?

You still need to sign up at 65 to avoid penalties, even if you are working. If your employer has 20 or more employees and covers you, you can delay Part B without penalty, but you should still enroll in Part A. If your employer has fewer than 20 employees, Medicare becomes primary at 65, and you should enroll in both parts.

Do I lose my current health insurance when I turn 65?

Not automatically. If you have employer coverage, it continues until you leave the job or lose coverage. However, Medicare becomes primary at 65 (or when you enroll, whichever is later). You will coordinate between your employer plan and Medicare. Talk to your employer's benefits office about how enrollment affects your coverage.

What happens if I turn 65 outside the United States?

You can still enroll in Medicare from abroad. You will need to sign up during your Initial Enrollment Period using Medicare.gov or by calling 1-800-MEDICARE. Some Medicare plans do not cover care outside the U.S., so review your options carefully if you live or travel internationally.

Can my spouse sign up for Medicare at a different age?

No, Medicare may be able to access is based on individual age. Your spouse becomes may be able to access at their own 65th birthday, regardless of when you enrolled. You each have your own Initial Enrollment Period and can choose different coverage plans.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.