When and how to sign up for Part A and Part B

You can sign up for Medicare Part A and Part B during your Initial Enrollment Period, which runs for seven months — three months before the month you turn 65, the month you turn 65, and three months after. If you miss this window, you can still sign up, but you may pay a permanent penalty on your Part B premium, and Part A coverage may not start right away.

Most people sign up through Social Security, either online at ssa.gov, by phone at 1-800-772-1213, or in person at a local Social Security office. You can also sign up through Medicare directly at medicare.gov or by calling 1-800-MEDICARE (1-800-633-4227). If you are still working and have health coverage through your employer, you may be able to delay Part B without penalty — but you must sign up for Part A on time.

The process takes about 15 minutes if you do it online, and you will need your Social Security number, birth date, and citizenship or immigration status. Coverage typically starts the first day of the month you turn 65, or the first day of the month after you sign up, depending on when you submit your information.

Key Takeaways

  • Your Initial Enrollment Period is seven months long — three months before you turn 65, the month you turn 65, and three months after — and missing it can cost you permanently higher premiums.
  • You can sign up through Social Security (online, by phone, or in person), through Medicare directly, or through your employer if you are still working.
  • Part A has no monthly premium for most people, but Part B costs a monthly amount that varies by income and changes each year.
  • If you are still employed and covered by your employer's health plan, you can delay Part B without penalty, but you must sign up for Part A when you turn 65.
  • Coverage usually starts on the first day of the month you turn 65 or the first day of the month after you sign up.

What documents you need to have ready

Before you start, gather your Social Security card (or your Social Security number), your birth certificate or passport, and proof of U.S. citizenship or legal residency. If you are explore by phone or in person, you may not need to show originals, but having them nearby helps if questions come up.

If you are signing up online at ssa.gov or medicare.gov, you will need to create or log into an account. This requires an email address and a password. If you do not have an online account, you can create one during the sign-up process — it takes a few extra minutes but lets you track your process and access your Medicare information later.

If you are still working and want to delay Part B, have your employer's health plan documents or insurance card ready so you can confirm the coverage details. You will also need to sign a form stating that you are covered by an employer plan — Social Security or Medicare will provide this form.

Signing up online through Social Security

Go to ssa.gov and look for the "explore for Benefits" section. Click on "Retirement Benefits" if you have not yet claimed Social Security, or "Medicare Only" if you have already claimed retirement benefits. You will be asked to create a my Social Security account if you do not have one.

The online form asks for your name, date of birth, Social Security number, citizenship status, and contact information. You will also answer questions about your work history and whether you want to claim retirement benefits at the same time. If you are delaying Part B because you are still working, select that option when prompted.

After you submit, you will receive a confirmation number. Social Security typically processes online applications within two weeks. You can check the status of your process by logging back into your my Social Security account. Medicare will send you a notice in the mail once your enrollment is complete, usually within 30 days.

Signing up by phone or in person

Call Social Security at 1-800-772-1213 (TTY 1-800-325-0778 for deaf and hard of hearing) Monday through Friday, 8 a.m. to 7 p.m. your local time. Have your Social Security number, birth date, and citizenship information ready. The call usually takes 10 to 15 minutes. You will receive a confirmation number and a notice in the mail within 30 days.

To explore in person, find your nearest Social Security office at ssa.gov/locator. Bring your Social Security card, birth certificate or passport, and proof of citizenship (such as a U.S. passport or naturalization certificate). You do not need an appointment at most offices, but you can schedule one online to avoid waiting. Processing time is the same as online — typically 30 days.

If you are deaf or hard of hearing, Social Security offers video relay services and TTY numbers. If you speak a language other than English, Social Security can provide an interpreter by phone at no cost — ask when you call.

Signing up through Medicare directly

You can also enroll through Medicare at medicare.gov or by calling 1-800-MEDICARE (1-800-633-4227). This route is useful if you do not have a Social Security account or prefer to work directly with Medicare. The process is similar: you provide your name, date of birth, Social Security number, and citizenship status.

Medicare processes applications and sends you a notice in the mail. Your enrollment is then forwarded to Social Security. This method takes slightly longer — usually 30 to 45 days — because the information has to move between two agencies, but the end result is the same.

If you call Medicare, have your information ready and expect to spend 15 to 20 minutes on the phone. Medicare representatives can also answer questions about your coverage, costs, and what Part A and Part B cover.

What happens if you miss your Initial Enrollment Period

If you do not sign up during your seven-month Initial Enrollment Period, you can still enroll later during the General Enrollment Period, which runs from January 1 to March 31 each year. Coverage starts July 1 of that year. However, you will pay a permanent 10% increase to your Part B premium for each full year you delayed — this penalty stays with you for life.

Part A does not usually have a penalty, but if you delayed Part A and did not have other may have access to coverage, you may have to pay a 10% premium increase as well. The only exception is if you were covered by an employer health plan while you were working — in that case, you can sign up for Part B without penalty during an eight-month period after your employment or coverage ends.

If you are past your Initial Enrollment Period and do not may have access to for an exception, wait for the General Enrollment Period (January 1 to March 31) to sign up. You can still use Social Security, Medicare, or your local Social Security office — the process is the same, but your coverage will not start until July 1.

Part A and Part B costs and what they cover

Part A has no monthly premium for most people who have worked and paid Medicare taxes for at least 10 years (40 quarters). If you do not meet this requirement, you may pay a monthly premium ranging from roughly $275 to $550, depending on how many quarters you worked — the exact amount changes each year.

Part B has a monthly premium that varies by income. In 2024, the standard premium is around $175 per month, but higher earners pay more through an income-related adjustment. The exact amount depends on your modified adjusted gross income from two years prior. You pay this premium whether you use Medicare or not.

Part A covers hospital stays, skilled nursing care, hospice, and some home health services. Part B covers doctor visits, outpatient care, lab tests, and preventive services. Both have deductibles and copayments that vary by service. You can view the current costs and coverage details at medicare.gov.

Frequently Asked Questions

Can I sign up for Part A without Part B?

Yes. You can enroll in Part A alone and delay Part B if you are still working and covered by an employer health plan. However, if you are not working or do not have employer coverage, it is usually better to sign up for both at the same time to avoid gaps in coverage and future penalties.

What if I am still working when I turn 65?

You must sign up for Part A when you turn 65. You can delay Part B without penalty if your employer health plan covers you. When you leave your job or lose coverage, you have eight months to sign up for Part B without a penalty. Tell Social Security or Medicare that you are still working when you explore.

How long does it take to get my Medicare card?

Medicare sends your card in the mail after your enrollment is processed, usually within 30 days of your sign-up date. You do not need the physical card to use Medicare — your coverage starts on the date your enrollment is approved. You can view your coverage details online at medicare.gov while you wait for the card to arrive.

What if I made a mistake on my process?

Contact Social Security or Medicare as soon as you notice the error. You can call Social Security at 1-800-772-1213 or Medicare at 1-800-MEDICARE. They can correct information like your name, date of birth, or citizenship status. If you enrolled in the wrong plan or missed your enrollment period, you may have limited options, so call right away.

Do I have to pay for Part A and Part B upfront?

No. Part A premiums (if you owe them) and Part B premiums are deducted automatically from your Social Security check each month, or you can pay by mail or online. You do not pay anything upfront when you sign up.