Where to sign up for Medicare Part B

You can sign up for Medicare Part B through Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. The easiest route for most people is Medicare.gov, where you can complete the process online without waiting on hold. If you prefer to speak with someone, the phone line is available seven days a week, and staff can walk you through each step. Social Security offices also handle Part B sign-ups, though wait times vary by location.

You do not need to visit an office or make a phone call if you are already receiving Social Security benefits — Medicare will contact you automatically about three months before your 65th birthday with information about Part B. If you want to sign up before that notice arrives, you can start the process on Medicare.gov at any time.

Key Takeaways

  • Medicare.gov is the fastest way to sign up for Part B online without waiting on the phone.
  • You can call 1-800-MEDICARE seven days a week to sign up by phone with a representative.
  • If you are already getting Social Security, Medicare will send you enrollment information automatically about three months before you turn 65.
  • Your Part B coverage start date depends on when you sign up during your initial enrollment period or a general enrollment period.
  • Missing your initial enrollment period without a valid reason can result in a permanent late penalty added to your Part B premium.

Timing matters: enrollment periods and start dates

Your initial enrollment period runs for seven months: three months before the month you turn 65, the month you turn 65, and three months after. If you sign up during this window, your coverage can start as early as the first day of the month you turn 65, depending on when you submit your information. For example, if you turn 65 in June and sign up in April, Part B coverage typically starts June 1. If you sign up in July (after your birthday), coverage usually starts August 1.

If you miss your initial enrollment period, you can sign up during the general enrollment period, which runs January 1 through March 31 each year. Coverage through the general enrollment period starts July 1 of that year. This means if you sign up in February, you will wait until July to have Part B coverage — a gap that could leave you without hospital insurance for months.

Signing up late also triggers a late enrollment penalty. This is a permanent increase to your Part B premium of about 10 percent for each full year you delayed after your initial enrollment period ended. If you waited three years to sign up, you would pay roughly 30 percent more than the standard premium for as long as you have Part B. This penalty does not go away.

What you will need to have ready

Before you start, gather your Social Security number, date of birth, and information about any current health coverage you have (such as employer insurance or COBRA). If you are signing up by phone or in person, having your Medicare card number helps, though you will receive this card only after you are enrolled.

You will also need to decide whether you want Part B coverage to start right away or at a later date. If you are still working and covered by your employer's health plan, you may want to delay Part B without penalty — but only if your employer has 20 or more employees. This is called creditable coverage, and it protects you from the late penalty. If you are unsure whether your employer plan qualifies, ask your benefits department before you sign up.

Signing up online through Medicare.gov

Go to Medicare.gov and look for the "Sign Up for Medicare" button on the homepage. You will be asked to create a Medicare.gov account or log in if you already have one. The account requires your email address and a password you create. Once logged in, you will answer questions about your age, citizenship, and current coverage.

The online form takes about 10 to 15 minutes to complete. You will confirm your personal information, review the coverage options available to you, and choose whether to enroll in Part B. At the end, you will see a confirmation page with a reference number — save or print this for your records. Medicare will send you a confirmation letter by mail within two weeks.

Signing up by phone

Call 1-800-MEDICARE (1-800-633-4227) and tell the representative you want to sign up for Medicare Part B. Have your Social Security number and date of birth ready. The representative will ask about your current coverage, citizenship, and whether you want Part B to start right away. The call usually takes 15 to 20 minutes.

Ask the representative for a confirmation number before you hang up, and write it down. You will receive a confirmation letter in the mail within two weeks. If you do not receive it after three weeks, call back with your confirmation number to check the status.

Signing up in person at Social Security

Visit your local Social Security office with your Social Security card, proof of citizenship (passport, birth certificate, or naturalization papers), and proof of residence (utility bill or lease). You can find your nearest office by going to ssa.gov and using the office locator tool. Call ahead to ask about current wait times — many offices now require appointments.

Bring the same information you would provide over the phone: your date of birth, current coverage details, and information about any employer health insurance. The staff member will complete the enrollment form with you and give you a receipt with a confirmation number. Keep this receipt until you receive your confirmation letter in the mail.

What happens after you sign up

Medicare will send you a confirmation letter within two to three weeks. This letter will tell you your Part B coverage start date and your premium amount. Your Medicare card will arrive separately, usually within two weeks of your coverage start date. The card shows your Medicare number, which you will need when you see doctors or go to the hospital.

Your Part B premium is normally deducted automatically from your Social Security check each month. If you are not yet receiving Social Security, Medicare will send you a bill. You can also set up automatic payments from your bank account through Medicare.gov if you prefer.

Frequently Asked Questions

Can I sign up for Part B after I turn 65?

Yes, but timing matters. If you sign up within three months after your birthday, coverage usually starts the following month. If you sign up more than three months after your birthday, you enter the general enrollment period, and coverage does not start until July 1 of that year. You will also owe a late penalty unless you had creditable coverage from an employer.

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

You may be able to delay Part B without penalty if your employer has 20 or more employees. This is called creditable coverage. Contact your employer's benefits department to confirm, then tell Medicare about your coverage when you sign up. Keep documentation of your employer coverage in case Medicare asks for proof later.

Do I have to sign up for Part B if I do not want it?

You are not required to sign up, but if you delay and do not have creditable coverage, you will owe a late penalty when you do enroll. The penalty is permanent and increases your premium for life. If you are unsure whether you need Part B, call 1-800-MEDICARE to discuss your situation with a representative.

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

Your confirmation letter arrives within two to three weeks. Your actual Medicare card arrives separately, usually within two weeks of your coverage start date. You can use your confirmation letter as proof of coverage with doctors until your card arrives.

What if I made a mistake on my sign-up form?

Call 1-800-MEDICARE with your confirmation number and tell them what needs to be corrected. They can update your information over the phone. Make sure to ask when the change will take effect, especially if it involves your coverage start date or premium.