Where to sign up depends on when you turn 65 and whether you already get Social Security

Most people sign up through Social Security, either online at ssa.gov or by visiting a local Social Security office. If you are already receiving Social Security benefits, Medicare enrollment happens automatically three months before your 65th birthday — you do not need to do anything. If you are not yet receiving Social Security, you will need to contact Social Security to enroll in Medicare at the same time.

You can also sign up directly through Medicare at medicare.gov or by calling 1-800-MEDICARE (1-800-633-4227). This route takes longer because Medicare then contacts Social Security on your behalf, but it works if you prefer not to visit a Social Security office. The important date to sign up is three months after the month you turn 65. Missing this important date can result in permanent penalties on your premiums, so marking your calendar matters.

Key Takeaways

  • If you receive Social Security, Medicare enrollment happens automatically three months before you turn 65 and requires no action on your part.
  • If you do not receive Social Security, contact Social Security to enroll in Medicare during the same process, either online at ssa.gov or at your local office.
  • You can also enroll directly through Medicare at medicare.gov or by calling 1-800-MEDICARE, though this takes longer.
  • Your enrollment important date is three months after the month you turn 65; missing it triggers permanent premium increases.
  • You will choose between Original Medicare (Parts A and B) and Medicare Advantage (Part C) during enrollment.

Signing up through Social Security online

Go to ssa.gov and look for the "Create my Social Security account" button on the homepage. You will need your email address, a password, and a way to verify your identity — usually a phone number or address on file with Social Security. Once your account is created, you can log in and look for the Medicare enrollment option.

The online process takes about 15 minutes. You will answer questions about your citizenship, work history, and whether you want Part A (hospital insurance), Part B (medical insurance), or both. You will also choose whether you want Original Medicare or a Medicare Advantage plan if one is available in your area. After you submit, you will receive a confirmation number by email.

Signing up at a Social Security office in person

Find your local office at ssa.gov/locator or call 1-800-772-1213. You can walk in during business hours, but calling ahead to schedule an appointment usually means shorter wait times. Bring your birth certificate, proof of citizenship (passport or naturalization papers), and proof of residence (a recent utility bill or lease).

The appointment takes 20 to 30 minutes. A representative will walk you through the same questions as the online form and help you choose your coverage. If you are not yet 65, you can still schedule this appointment up to four months before your birthday. The office will mail you your Medicare card within two weeks of approval.

Signing up directly through Medicare

Visit medicare.gov and select "Sign up for Medicare" or call 1-800-MEDICARE. You will provide your name, date of birth, and Social Security number. Medicare will ask whether you are currently receiving Social Security benefits. If you are not, Medicare will contact Social Security to start your benefits at the same time as your Medicare enrollment.

This process takes longer — usually four to six weeks — because Medicare and Social Security have to coordinate. You will still receive your Medicare card by mail, and your coverage will start on the first day of the month you turn 65 (or the first day of the month after you enroll, if you enroll after turning 65). Keep your confirmation number from the call or online submission in case you need to check your status.

What happens after you sign up

You will receive a Medicare card in the mail within two weeks to two months, depending on how you enrolled. This card shows your Medicare number and which parts of Medicare you have. Do not wait for the card to start using your benefits — your coverage begins on the date Medicare confirms, even if the card has not arrived.

If you chose Original Medicare (Parts A and B), you can use your benefits at any hospital or doctor that accepts Medicare. If you chose a Medicare Advantage plan, your coverage is limited to doctors and hospitals in that plan's network, with some exceptions for emergencies. You may also want to look into prescription drug coverage (Part D) and supplemental insurance (Medigap) if you did not choose Medicare Advantage, since Original Medicare does not cover everything.

What to do if you missed the enrollment important date

If you are past the three-month window after your 65th birthday, you can still enroll, but you may face a permanent penalty. For every 12 months you delayed Part B enrollment, your premium increases by 10 percent for as long as you have Medicare. For every month you delayed Part D (prescription drug coverage), your premium increases by 1 percent per month.

Contact Social Security or Medicare right away to enroll. Explain your situation — some people have valid reasons for late enrollment (such as still working and covered by an employer plan) that waive the penalty. Bring documentation if you have it: a letter from your employer confirming coverage, or proof that you were working past 65. The sooner you enroll, the sooner the penalty stops growing.

Documents you will need to have ready

The documents you need depend on which enrollment method you choose. If you enroll online at ssa.gov, you will need an email address and a phone number or address on file with Social Security to verify your identity. If you visit a Social Security office in person, bring your birth certificate, proof of citizenship (a passport or naturalization papers), and proof of residence (a recent utility bill or lease).

If you enroll by phone with Social Security, have your Social Security number, date of birth, and citizenship status ready. If you enroll directly through Medicare at medicare.gov or by phone, you will need your name, date of birth, and Social Security number. None of these methods require you to have all documents in hand before you start — you can gather them as you go through the process.

Frequently Asked Questions

Can I sign up for Medicare before I turn 65?

Yes. You can enroll starting three months before the month you turn 65. For example, if your birthday is in June, you can enroll starting in March. Your coverage will begin on the first day of the month you turn 65, regardless of when during that three-month window you sign up.

What if I am still working at 65 and have health insurance through my job?

You should still enroll in Medicare Part A (hospital insurance) at 65, even if you delay Part B. If you wait to enroll in Part B after you leave your job, you may avoid the late penalty if you have employer coverage. Bring a letter from your employer confirming your coverage when you enroll, so Medicare knows you had a valid reason to delay.

Do I have to choose a Medicare Advantage plan during enrollment, or can I switch later?

You do not have to choose during your initial enrollment. If you choose Original Medicare at first, you can switch to a Medicare Advantage plan during the annual enrollment period (October 15 to December 7 each year). However, if you switch from Medicare Advantage back to Original Medicare, you may want to enroll in a Medigap plan at the same time, and waiting can make that more expensive.

What if I do not have a birth certificate or proof of citizenship?

Call your local Social Security office at 1-800-772-1213 and explain what documents you have. Social Security can accept alternatives — such as a driver's license, passport, or military discharge papers — depending on your situation. The office can tell you what will work before you visit.

How do I know if my Medicare enrollment went through?

You will receive a confirmation number when you enroll online or by phone. Write it down. You can check your status anytime at ssa.gov (if you enrolled through Social Security) or medicare.gov (if you enrolled through Medicare). Your Medicare card will arrive in the mail, but your coverage starts on the official date even before the card arrives.