How to Sign Up for Medicare Part B

When and How to Sign Up for Medicare Part B

You sign up for Medicare Part B during your Initial Enrollment Period, which runs for seven months: the three months before you turn 65, the month you turn 65, and the three months after. If you miss this window, you can still sign up later, but you will pay a higher monthly premium for as long as you have Part B — a permanent penalty of 10 percent per year you delayed.

You can sign up through three routes: 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 if you have your Social Security number and Medicare number handy. The phone line has wait times but staff can walk you through the form step by step. In-person signup at Social Security takes longer but works if you need help with documents.

The signup process itself takes about 10 minutes online or 15 to 20 minutes on the phone. You will need to confirm your identity, choose your coverage start date, and decide whether you want Part B at all — it is not automatic, and some people delay it if they still have employer coverage.

Key Takeaways

Your Initial Enrollment Period is seven months long: three months before you turn 65, the month of your birthday, and three months after.
Signing up late costs you 10 percent more per month for every year you waited, and that penalty stays with you permanently.
You can sign up online at Medicare.gov, by phone at 1-800-MEDICARE, or at your local Social Security office.
Part B is not automatic — you must actively choose it, and some people with employer coverage delay it without penalty.

What Documents You Need to Have Ready

You will need your Social Security number and your Medicare number. If you do not have your Medicare number yet, you can still sign up — Medicare will assign one during the process. You should also have your current mailing address and phone number.

If you are signing up by phone or in person, bring a photo ID and proof of citizenship or legal residency — a birth certificate, passport, or naturalization papers work. If you are explore in person at Social Security, bring your original documents or certified copies; they will not accept photocopies.

If you have employer coverage and want to delay Part B without penalty, you will need to show proof that the coverage is active — usually a letter from your employer's benefits office or a copy of your health plan card. Keep this document; you may need it later to prove you had coverage when you delayed.

Signing Up Online at Medicare.gov

Go to Medicare.gov and click "Sign Up for Medicare" in the top menu. You will be asked to create a login or use an existing one. The form asks for your name, date of birth, Social Security number, and contact information.

You will then choose your coverage start date. If you are within your Initial Enrollment Period, you can usually start coverage on the first of any month. If you sign up between the 1st and 15th of a month, coverage starts the first of the next month. If you sign up between the 16th and the end of a month, coverage starts the first of the month after that.

After you submit, you will see a confirmation number on screen. Write it down or take a screenshot. Medicare will also send a confirmation email and a paper notice in the mail within two weeks. Your Medicare card should arrive within two to four weeks after that.

Signing Up by Phone

Call 1-800-MEDICARE (1-800-633-4227). Wait times are usually shortest early in the morning or late in the afternoon on weekdays. Have your Social Security number ready when you call.

The representative will ask the same questions as the online form: name, date of birth, address, and phone number. They will confirm your coverage start date and answer any questions about what Part B covers. At the end of the call, they will give you a confirmation number — ask them to repeat it and write it down.

You will receive a paper confirmation in the mail within two weeks and your Medicare card within two to four weeks. If you do not receive your card by then, call back with your confirmation number and they can check the status.

Signing Up In Person at Social Security

Find your local Social Security office at ssa.gov/locator or call 1-800-772-1213. You can walk in during business hours, but many offices now require you to make an appointment first. Bring your original birth certificate, passport, or naturalization papers; a photo ID; and your Social Security card if you have it.

The staff member will fill out the Medicare Part B form with you and answer questions about your coverage options. The process usually takes 20 to 30 minutes. You will receive a receipt with a confirmation number before you leave.

Your Medicare card will be mailed to you within two to four weeks. If you need proof of coverage before the card arrives, ask for a printout at the Social Security office — they can give you a temporary document you can show to doctors or insurers.

What Happens If You Miss Your Initial Enrollment Period

If you turn 65 and do not sign up for Part B during your seven-month window, you can still sign up 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 percent premium increase for every 12 months you delayed. If you waited two years, your premium goes up 20 percent. If you waited five years, it goes up 50 percent. This penalty applies for as long as you have Part B and does not go away.

The only exception is if you had creditable coverage — employer health insurance or coverage from a spouse's employer — during the time you delayed. If you can prove you had that coverage, you can sign up without penalty. You will need a letter from your employer's benefits office stating the dates you were covered and that the plan was creditable.

Part B Costs and What It Covers

Part B has a monthly premium that changes each year. In 2024, the standard premium is $164.90 per month for most people, though higher earners pay more. You also pay a yearly deductible (currently $240) before Part B starts paying its share, and then you pay 20 percent of the cost of most services after that.

Part B covers doctor visits, outpatient hospital care, medical equipment, and preventive services like cancer screenings and vaccines. It does not cover dental, vision, hearing aids, or long-term care. Many people buy a Medigap or Medicare Advantage plan to cover the costs Part B does not pay.

Your premium is usually taken directly from your Social Security check each month. If you do not receive Social Security, Medicare will bill you by mail. You can change how you pay by calling 1-800-MEDICARE.

Frequently Asked Questions

Can I sign up for Part B after I turn 65 if I still have employer health insurance?

Yes. If your employer has 20 or more employees, you can delay Part B without penalty as long as you are actively employed and covered by the plan. Once you leave the job or lose the coverage, you have eight months to sign up for Part B without paying the late penalty. Keep proof of your coverage dates from your employer.

What if I sign up for Part B but change my mind?

You can drop Part B, but only during the General Enrollment Period (January 1 to March 31). If you drop it and want it back later, you will pay the late penalty unless you have creditable coverage to show. It is usually better to keep Part B once you have it.

Do I have to sign up for Part A and Part B at the same time?

No. Part A (hospital insurance) is usually automatic at 65 if you receive Social Security. Part B (doctor and outpatient care) requires you to actively sign up. You can have Part A without Part B, though most people get both.

How long does it take to get my Medicare card after I sign up?

Your card usually arrives within two to four weeks. If you need proof of coverage before it arrives, you can print a temporary notice from your Medicare account at Medicare.gov, or call 1-800-MEDICARE and ask them to mail you a temporary document.

What if I signed up online but never got a confirmation email?

Check your spam folder first. If it is not there, log back into Medicare.gov and go to your account — you should see your enrollment status and confirmation number there. If you still cannot find it, call 1-800-MEDICARE with your Social Security number and they can look up your enrollment.

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.