When and how to sign up for Medicare

You can sign up for Medicare starting three months before you turn 65, during your birth month, and for three months after. This seven-month window is called your Initial Enrollment Period. If you sign up during this window, your coverage usually starts on the first day of the month you turn 65.

You have three main ways to sign up: online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. Online is fastest — you can complete it in about 10 minutes if you have your Social Security number and birth certificate information ready. The phone line has wait times but staff can walk you through each question. In-person signup at Social Security takes longer but works well if you prefer to sit with someone.

If you miss your Initial Enrollment Period, you can still sign up, but you may pay a permanent penalty on your premiums. The penalty is 10% of the Part B premium for each full 12 months you were may be able to access but did not sign up. This penalty stays with you for life, so signing up as soon as you realize you missed the important date matters.

Key Takeaways

  • Your Initial Enrollment Period runs for seven months: three months before you turn 65, your birth month, and three months after.
  • You can sign up online at Medicare.gov, by phone at 1-800-MEDICARE, or at your local Social Security office.
  • If you miss your Initial Enrollment Period, you will pay a permanent 10% penalty on Part B premiums for each year you delayed.
  • Part A (hospital insurance) is usually free if you or your spouse paid Medicare taxes for at least 10 years; Part B (doctor visits) costs a monthly premium that varies by income.
  • You must choose between Original Medicare (Parts A and B) and Medicare Advantage (Part C), and you can add prescription drug coverage (Part D) to either.

What you need to have ready before you sign up

Gather your Social Security number, birth certificate or passport, and proof of citizenship or legal residency before you start. You will also need information about any current health insurance you have — employer coverage, COBRA, or a marketplace plan — because this affects when you can sign up without penalty.

If you are signing up by phone or in person, have a list of any medications you take and the pharmacies where you fill them. This is not required to sign up, but it helps you choose a prescription drug plan (Part D) that covers what you actually use. If you are signing up online, you can add this information later.

Understanding Part A, Part B, and your choices

Part A covers hospital stays, skilled nursing care, hospice, and some home health services. Most people do not pay a monthly premium for Part A if they or their spouse paid Medicare taxes for at least 10 years while working. If you do not meet this requirement, Part A costs around $278 to $556 per month in 2024, depending on how many quarters of Medicare taxes you paid. When you sign up, you are automatically enrolled in Part A unless you decline it in writing.

Part B covers doctor visits, outpatient care, lab tests, and medical equipment. Part B has a monthly premium that changes each year — in 2024 it starts at $164.90 per month for most people, but costs more if your income is higher. You must choose whether to enroll in Part B when you sign up for Part A. If you delay Part B and do not have other may have access to coverage, you will owe a permanent 10% penalty.

After you enroll in Parts A and B, you choose between two paths: Original Medicare (Parts A and B together) or Medicare Advantage (Part C). Original Medicare is run by the federal government and covers the services listed above at any hospital or doctor that accepts Medicare. Medicare Advantage is run by private insurance companies and usually costs less in premiums, but limits you to a network of doctors and hospitals. You cannot have both at the same time.

Adding prescription drug coverage (Part D)

If you choose Original Medicare, you should add Part D (prescription drug coverage) during your Initial Enrollment Period. Part D is sold by private insurance companies and covers the cost of medications. If you do not sign up during your Initial Enrollment Period and you do not have other may have access to drug coverage, you will pay a permanent penalty of about 1% of the national average Part D premium for each month you delay — this penalty is added to your premium for life.

If you choose Medicare Advantage, drug coverage is usually included in the plan, so you do not need to buy Part D separately. Check the plan details to see which drugs are covered and at what cost.

You can change your Part D plan or add it later during the Annual Enrollment Period (October 15 to December 7 each year), but you will owe the late penalty if you did not have coverage in the months between your Initial Enrollment Period and when you sign up.

If you are still working or have employer coverage

If you or your spouse are still working and have health insurance through an employer, you may be able to delay Part B without penalty. This is called creditable coverage. You must sign up for Part A when you turn 65, but you can wait to sign up for Part B until you or your spouse leave the job or lose the coverage.

When you do leave work, you have eight months to sign up for Part B without penalty. This period starts the month after your employment or coverage ends. You will need a letter from your employer stating the dates you had coverage and confirming it was creditable. Keep this letter — you may need it to prove you should not owe a penalty.

If you have coverage through a spouse's employer, the same rules explore, but the eight-month window starts when your spouse leaves the job or when you turn 65, whichever is later.

Signing up online at Medicare.gov

Go to Medicare.gov and click "Sign up for Medicare" in the top menu. You will create a login using your email address and a password. Answer questions about your age, citizenship, and whether you have current health insurance. The site will ask if you want Part A, Part B, or both. Choose yes for both unless you have employer coverage and are delaying Part B.

Next, you will choose between Original Medicare and Medicare Advantage. If you choose Original Medicare, the site will ask if you want to add Part D. Select a plan or plans that match your doctors and medications. Review your choices, then submit. You should receive a confirmation email right away and a Medicare card in the mail within two weeks.

Signing up by phone or in person

Call 1-800-MEDICARE (1-800-633-4227) Monday through Friday, 8 a.m. to 8 p.m. Eastern time. Have your Social Security number and birth certificate information ready. A representative will ask the same questions as the online form and can explain your choices. The call usually takes 20 to 30 minutes. You will receive a confirmation number and a Medicare card in the mail.

To sign up in person, visit your local Social Security office. Find the nearest office at ssa.gov or call 1-800-772-1213. Bring your Social Security card, birth certificate, and proof of citizenship. An employee will complete the form with you. This takes longer than phone or online but can be helpful if you have complex questions or prefer face-to-face help.

What happens after you sign up

Medicare will mail you a Medicare card within two weeks of your signup date. This card shows your Medicare number and which parts you are enrolled in. Keep it in a safe place and bring it to every doctor visit and hospital stay.

If you chose Original Medicare, your coverage starts on the first day of the month you turn 65 (or the first day of the month after you sign up, if you sign up after your birthday). If you chose Medicare Advantage, your coverage starts on the first day of the following month. You will receive bills for your Part B premium and any Part D premium starting the month coverage begins.

You can change your Medicare plan once a year during the Annual Enrollment Period (October 15 to December 7). Outside this window, you can only change plans if you have a may have access to life event, such as moving out of your plan's service area or losing other health coverage.

Frequently Asked Questions

What if I am not a U.S. citizen?

You must be a U.S. citizen or a lawful permanent resident (green card holder) who has lived in the United States for at least five consecutive years. Bring your green card or other proof of legal residency when you sign up. If you do not meet these requirements, you cannot enroll in Medicare.

Can I sign up for Medicare before I turn 65?

Yes. You can sign up starting three months before your 65th birthday. Many people sign up at age 64 and a half to make sure their coverage starts on time. Signing up early also gives you time to choose a plan and ask questions.

What if I miss the important date to sign up?

You can sign up after your Initial Enrollment Period ends, but you will owe a permanent penalty on Part B and Part D premiums. The penalty is 10% of the Part B premium for each 12 months you were may be able to access but did not sign up. Contact Social Security or Medicare as soon as you realize you missed the important date to minimize the penalty.

Do I have to sign up for Part B if I have employer coverage?

No. If you or your spouse are still working and have health insurance through an employer, you can delay Part B without penalty. You must sign up for Part A, but you have until eight months after you leave the job to sign up for Part B penalty-free. Get a letter from your employer confirming your coverage dates.

Can I change my mind after I sign up?

Yes, but only during certain times. You have until the end of the year you turn 65 to make changes to your Initial Enrollment choices. After that, you can change plans only during the Annual Enrollment Period (October 15 to December 7) or if you have a may have access to life event like moving or losing coverage.