When and Where to Sign Up

You sign up for Medicare through Social Security, either online at ssa.gov, by phone at 1-800-772-1213, or in person at your local Social Security office. Most people become may be able to access at 65, and you can start the process three months before that birthday. If you miss the window around your 65th birthday, you can still sign up later, but you may pay a permanent penalty on your premiums.

The easiest route is online at ssa.gov — you can complete the whole process from home in about 15 minutes. You will need your Social Security number, birth certificate, proof of citizenship or legal residency, and information about any current health coverage. If you prefer to talk to someone, call Social Security and they will walk you through it over the phone or schedule an appointment at an office near you.

Key Takeaways

  • You sign up through Social Security, not Medicare directly, starting three months before you turn 65.
  • Online signup at ssa.gov is fastest; by phone (1-800-772-1213) and in-person appointments are also available.
  • You will need your Social Security number, birth certificate, proof of citizenship, and details of any current coverage.
  • If you delay past your 65th birthday without a valid reason, your premiums will be higher for life.
  • Medicare Part A (hospital) is usually automatic if you have paid into Social Security; Part B (doctor visits) requires you to choose it.

What Documents to Bring or Have Ready

Gather these before you start: your Social Security number, birth certificate, proof of U.S. citizenship or legal residency (passport, naturalization papers, or green card), and your current health insurance information if you have it. If you are signing up online, you can upload images of these documents or type in the information. If you are going in person or calling, have them nearby so you can answer questions about them.

If you are already receiving Social Security benefits, the process is simpler — Social Security already has most of what they need. You will mainly confirm that you want Medicare and choose which parts you want. If you are not yet receiving Social Security, you will sign up for both at the same time.

Choosing Between Part A, Part B, and Part D

Part A covers hospital stays, skilled nursing care, and hospice. For most people, it is automatic — if you or your spouse paid into Social Security for at least 10 years, you get Part A with no premium. You do not have to do anything to get it, but you still need to sign up for Medicare overall.

Part B covers doctor visits, outpatient care, and preventive services. It costs a monthly premium (the amount depends on your income). You have to choose whether to take it. If you delay Part B without a valid reason — such as having employer coverage — you will pay a penalty for as long as you have Medicare.

Part D is prescription drug coverage. It is optional, but if you go without it and later sign up, you may pay a penalty. You choose a Part D plan from private insurers, not from Social Security. You can pick a plan during your initial signup or wait until the annual open enrollment period (October 15 to December 7 each year).

The Timeline From Signup to Coverage

Coverage usually starts on the first day of the month in which you turn 65, or the first day of the month after you sign up — whichever is later. If you sign up in January and turn 65 in March, coverage starts March 1. If you turn 65 in March and do not sign up until May, coverage starts June 1.

You will receive your Medicare card in the mail within two to four weeks of signing up. Until it arrives, you can use a temporary notice from Social Security to show you are covered. Your card will have your Medicare number on it — keep it safe, as you will need it for doctor visits and prescriptions.

What Happens If You Miss the Signup Window

If you do not sign up within three months before or after your 65th birthday, you can still sign up later during the General Enrollment Period (January 1 to March 31 each year). However, your Part B premium will be 10 percent higher for each full year you delayed — and that increase is permanent.

There are exceptions: if you were covered by an employer health plan (yours or your spouse's) when you turned 65, you have eight months after that coverage ends to sign up without penalty. If you are a federal employee or a member of certain other groups, different rules may explore. When you do sign up late, bring documentation of your employer coverage so Social Security can waive the penalty.

Coordinating With Employer Coverage or Medicaid

If you are still working and your employer offers health coverage, you may not need to sign up for Part B right away — but you must still sign up for Part A. When your employer coverage ends, you have eight months to sign up for Part B without penalty. Tell Social Security about your employer coverage when you sign up; they will note it in your file.

If you are on Medicaid, signing up for Medicare does not end your Medicaid coverage. In fact, you will likely stay on both — Medicare becomes your primary insurance and Medicaid helps with costs Medicare does not cover. When you sign up for Medicare, notify your state Medicaid office as well so they can coordinate the two programs.

After You Sign Up: What Comes Next

Once you are signed up, your coverage is active on your start date even if your card has not arrived. You can start using Medicare when ready at any hospital, doctor's office, or pharmacy that accepts Medicare. When your card arrives, bring it to your appointments.

Within the first few months, you will also need to choose a Part D drug plan if you want prescription coverage. You can do this during your initial signup window or during the annual open enrollment period. If you have questions about your coverage or need to make changes, you can call Medicare directly at 1-800-MEDICARE (1-800-633-4227).

Frequently Asked Questions

Can I sign up for Medicare before I turn 65?

Yes. You can start the process three months before your 65th birthday. Social Security recommends signing up about three months early so your coverage starts on your birthday without a gap. If you sign up earlier than that, they will hold your process and process it closer to your birthday.

What if I am still working at 65 — do I have to sign up?

You must sign up for Part A (hospital coverage) at 65 even if you are working. You can delay Part B if your employer has 20 or more employees and you are covered under their plan. When you leave that job, you have eight months to sign up for Part B without penalty. Always sign up for Part A to avoid gaps in coverage.

Do I have to choose a Medicare Advantage plan during signup?

No. During initial signup, you are choosing Original Medicare (Part A and Part B) or deciding to delay Part B. Medicare Advantage plans are a separate choice you make after you have Original Medicare. You can pick an Advantage plan during your initial enrollment period or during the annual open enrollment period in the fall.

What if I miss the three-month window before my birthday?

You can still sign up during the General Enrollment Period (January 1 to March 31). However, your Part B premium will be 10 percent higher for each full year you delayed. If you had employer coverage when you turned 65, you have eight months after that coverage ends to sign up without penalty — bring proof of that coverage.

Can I sign up for Medicare online if I do not have a Social Security account?

You can start the process online at ssa.gov without an account, but you may need to create one to complete it. If you run into trouble, call Social Security at 1-800-772-1213 and they will help you finish over the phone or schedule an in-person appointment instead.