Who Gets Medicare and When You Become Eligible

The Basic Rule: Age 65 or Disability

You become may be able to access for Medicare when you turn 65, or sooner if you have been receiving Social Security Disability Insurance (SSDI) for 24 months, or if you have end-stage renal disease or ALS. Most people do not have to do anything to sign up at 65 — if you are already getting Social Security retirement benefits, Medicare enrollment happens automatically three months before your 65th birthday. If you are not yet taking Social Security, you will need to sign up for Medicare yourself during your enrollment window.

The rule is the same whether you were born in the United States or became a citizen later. You do need to have worked long enough to have earned Social Security credits — generally 40 credits over your lifetime, which is about 10 years of work. If you have not worked that long yourself, you may still be covered as a spouse or widow or widower of someone who did.

Key Takeaways

You are may be able to access for Medicare at 65 if you have worked and paid Social Security taxes for about 10 years, or sooner if you receive disability benefits.
If you are already getting Social Security retirement checks, Medicare enrollment is automatic; if not, you must sign up during your enrollment window or face a permanent penalty.
You can sign up online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
Signing up late costs more — you pay a higher monthly premium for Part B and Part D for as long as you have Medicare, unless you have other coverage that counts as "creditable".

When Your Enrollment Window Opens and Closes

Your enrollment window is seven months long and centers on your birthday month. It starts three months before the month you turn 65 and ends three months after. For example, if you turn 65 in June, you can sign up from March through September. During this window, you can sign up without penalty, even if you do not need coverage right away.

If you miss this window and do not have other health coverage that counts as "creditable" — meaning it is as good as or better than Medicare — you will pay a permanent penalty. For Part B, the penalty is 10 percent of the standard premium for each full year you were may be able to access but not signed up. For Part D (prescription drug coverage), the penalty is 1 percent of the national average premium for each month you were without coverage. These penalties stay with you for life, even after you finally sign up.

There is one exception: if you or your spouse are still working and covered by your employer's health plan, you may be able to delay Part B without penalty. You will need to show proof that you have employer coverage. Part A (hospital insurance) has no penalty for late enrollment, so you can sign up for that anytime.

How to Sign Up

You have three ways to sign up: online, by phone, or in person. The online route is the fastest. Go to Medicare.gov, click "Sign Up for Medicare," and follow the steps. You will need your Social Security number, date of birth, and citizenship or immigration status. The process takes about 15 minutes.

If you prefer to talk to someone, call 1-800-MEDICARE (1-800-633-4227). Representatives are available Monday through Friday, 8 a.m. to 8 p.m. Eastern time, and Saturday 9 a.m. to 1 p.m. Eastern time. They can walk you through the questions and answer questions about which parts of Medicare you need.

You can also visit your local Social Security office in person. Bring your Social Security card, proof of citizenship or legal residency (passport, birth certificate, or naturalization papers), and proof of age. Staff there can help you sign up for Medicare at the same time you handle any Social Security business.

What Happens If You Are Already on Disability

If you have been receiving SSDI for 24 months, you automatically become may be able to access for Medicare Part A and Part B. You do not have to wait until 65. Medicare enrollment happens automatically — you do not need to sign up. Your coverage begins in the 25th month of your disability benefits.

The same rule applies if you have end-stage renal disease (permanent kidney failure requiring dialysis or a transplant) or ALS (amyotrophic lateral sclerosis, also called Lou Gehrig's disease). You become may be able to access for Medicare when ready upon diagnosis, regardless of age or work history. Social Security will contact you about enrollment.

Coverage as a Spouse or Widow or Widower

You may be may be able to access for Medicare based on your spouse's or ex-spouse's work record, even if you have not worked enough yourself. If you are married to someone 65 or older who is may be able to access for Medicare, you can sign up at 65 based on their record. If your spouse has passed away, you can sign up at 60 based on their record — or at 50 if you are disabled.

To sign up this way, you will need to prove your relationship: a marriage certificate for a current spouse, a divorce decree and proof of marriage for an ex-spouse, or a death certificate for a widow or widower. You can bring these documents when you sign up online, by phone, or in person.

What to Ask Your Doctor Before You Turn 65

Before your enrollment window opens, talk to your current doctor about what coverage you will need. Ask whether they accept Medicare and which Medicare plans they work with. Ask about any prescriptions you take regularly — some are covered better under certain Part D plans than others. If you see a specialist, ask whether they accept Medicare too.

If you have a chronic condition like diabetes or heart disease, ask your doctor which parts of Medicare matter most for your care. Some people need Part B more urgently than others. Your doctor can also tell you whether you should look into a Medicare Advantage plan (Part C) or stick with Original Medicare (Parts A and B) plus a separate Medigap or Part D plan.

When to Seek Help

Contact Social Security or Medicare if you are within three months of your 65th birthday and have not yet signed up, or if you turned 65 more than seven months ago and did not enroll. The sooner you contact them, the sooner your coverage can start. If you missed your window, they can tell you whether you owe a penalty and help you sign up now.

If you are on disability and approaching 24 months of SSDI benefits, watch for a letter from Social Security about your Medicare enrollment. If you do not receive one by the time you hit 24 months, call Social Security at 1-800-772-1213 to confirm your enrollment is on track.

Frequently Asked Questions

What if I am still working at 65?

You can still sign up for Medicare at 65 even if you are working. If your employer offers health coverage, you can delay Part B without penalty as long as you have that coverage and your employer has 20 or more employees. You must sign up for Part A (hospital insurance) at 65 regardless. When you leave your job or lose employer coverage, you have eight months to sign up for Part B without penalty.

Do I have to sign up for all parts of Medicare?

No. Part A (hospital insurance) is automatic if you are on Social Security. Part B (doctor visits) is optional but recommended — if you do not sign up when you are first may be able to access and do not have other coverage, you will pay a penalty. Part D (prescription drugs) is optional but has a penalty if you go without it and later sign up. Part C (Medicare Advantage) is optional and replaces Parts A and B.

What if I do not have a Social Security number?

You can still sign up for Medicare if you are a U.S. citizen or permanent resident without a Social Security number. You will need to explore for one at the same time you sign up for Medicare, or bring proof that you have applied. Contact Social Security or Medicare for the specific documents you will need to bring.

Can I sign up for Medicare before my 65th birthday?

Yes. Your enrollment window opens three months before your birthday month, so you can sign up as early as three months before you turn 65. Signing up early does not change your coverage start date — it will still begin the first day of the month you turn 65.

What happens to my current health insurance when I turn 65?

That depends on what coverage you have. If you have employer coverage, you can keep it and delay Medicare Part B without penalty. If you have an individual plan you bought yourself, you should contact your insurance company to ask what happens when Medicare starts. Some people keep both for a period of time; others switch to Medicare only.

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.