How to Enroll in Medicare Part A When You Turn 65

You enroll in Medicare Part A during your Initial Enrollment Period, which starts three months before the month you turn 65

Most people become automatically enrolled in Medicare Part A the month they turn 65 if they have been receiving Social Security benefits for at least four months. If you are automatically enrolled, you do not need to do anything — your Part A coverage begins on the first day of the month you turn 65, and your red, white, and blue Medicare card will arrive in the mail about two weeks before that date.

If you are not automatically enrolled — for example, if you delayed claiming Social Security — you must enroll yourself during your Initial Enrollment Period. This period runs for seven months: it starts three months before the month you turn 65, includes the month you turn 65, and ends three months after. If you miss this window, you may face a permanent penalty on your Part A premiums, so timing matters.

Key Takeaways

Most people are automatically enrolled in Part A the month they turn 65 if they have been receiving Social Security for at least four months.
If you are not automatically enrolled, you must enroll during your seven-month Initial Enrollment Period, which begins three months before you turn 65.
You can enroll online through Medicare.gov, by phone at 1-800-MEDICARE, by mail, or in person at your local Social Security office.
If you delay enrollment past your Initial Enrollment Period without a valid reason, you will pay a higher Part A premium for as long as you have Medicare.

How to enroll online through Medicare.gov

The fastest way to enroll is online at Medicare.gov. Go to the homepage and look for the "Sign up for Medicare" button. You will need to create a Medicare.gov account or log in if you already have one. You will be asked for your Social Security number, date of birth, and contact information.

The online form takes about 10 to 15 minutes. After you submit it, you will receive a confirmation number on screen and by email. Medicare will process your enrollment and send your card by mail within two to three weeks. You can check the status of your process anytime by logging back into your Medicare.gov account.

Enrolling by phone or mail

If you prefer not to enroll online, you can call 1-800-MEDICARE (1-800-633-4227). Representatives are available Monday through Friday, 8 a.m. to 8 p.m. Eastern time, and Saturday 9 a.m. to 1 p.m. Eastern time. Have your Social Security number and date of birth ready. The representative will walk you through the enrollment process over the phone, and you will receive a confirmation number before you hang up.

You can also enroll by mail. read the CMS-40B form from Medicare.gov, fill it out, and mail it to your local Social Security office. You can find the address on the Social Security website or by calling 1-800-772-1213. Mail enrollment takes longer — typically four to six weeks — so use this method only if you have time before your important date.

Enrolling in person at Social Security

Visit your local Social Security office in person to enroll. Bring your Social Security card, proof of citizenship or legal residency (such as a passport or birth certificate), and proof of age. You can find your nearest office by going to ssa.gov and using the office locator, or by calling 1-800-772-1213.

Social Security staff will complete your enrollment on the spot and give you a receipt. Your Medicare card will arrive by mail within two to three weeks. This method works well if you have questions or prefer to speak with someone face-to-face, but plan ahead — offices can have wait times, especially near the end of the month.

What happens if you enroll late

If you do not enroll during your seven-month Initial Enrollment Period and you do not have a valid reason for the delay, you will pay a late enrollment penalty. The penalty is a percentage of the Part A premium amount, and it increases for each 12-month period you were not enrolled. More importantly, this penalty is permanent — you will pay it for as long as you have Medicare, even if you enroll years later.

A valid reason for late enrollment includes having group health coverage through an employer or spouse's employer, or having end-stage renal disease. If you had one of these situations, you may be able to enroll without penalty during a Special Enrollment Period. Contact Medicare at 1-800-MEDICARE to explain your situation and ask whether you may have access to.

What you need to have ready

Before you enroll, gather these documents: your Social Security number, your date of birth, your citizenship or legal residency status (such as a passport, birth certificate, or green card), and your current mailing address. If you are enrolling by phone or in person, have your phone number and email address available as well.

If you are not automatically enrolled and you have had recent changes to your income or living situation, have that information ready too — it may affect whether you may have access to for help paying your premiums. You do not need to have any other insurance in place before you enroll in Part A.

Understanding your Part A coverage start date

Your Part A coverage begins on the first day of the month you turn 65 if you are automatically enrolled or if you enroll before that month ends. If you enroll after the month you turn 65 has passed, your coverage begins on the first day of the month after you enroll. For example, if you turn 65 in June but do not enroll until August, your Part A coverage will start September 1.

Your Medicare card will arrive by mail before your coverage begins. Keep it in a safe place — you will need to show it to doctors, hospitals, and other providers. If your card does not arrive within three weeks of enrollment, or if it arrives with errors, call 1-800-MEDICARE to request a replacement.

Frequently Asked Questions

Do I have to enroll in Part B at the same time as Part A?

No. Part A and Part B are separate, and you can enroll in them at different times. However, if you do not enroll in Part B when you are first may be able to access, you may face a late enrollment penalty on your Part B premium. Talk to Medicare about your options during your Initial Enrollment Period.

What if I am still working at 65 and have employer health insurance?

You can delay enrolling in Part A without penalty if you have group health coverage through your job or your spouse's job. When you or your spouse stops working or lose that coverage, you will have eight months to enroll in Part A without penalty. Contact Medicare to report the change.

Can someone enroll me if I am unable to do it myself?

Yes. A family member, friend, or representative can enroll you by phone or mail, or they can go with you to your local Social Security office. If you need a legal representative to handle your affairs, they can enroll you as well. Have them call 1-800-MEDICARE with your information.

Will I receive a bill for Part A premiums?

Most people do not pay a Part A premium because they or their spouse paid Medicare taxes while working. If you do owe a premium, it will be deducted from your Social Security check automatically. Medicare will tell you the amount when you enroll.

What if I miss my Initial Enrollment Period?

You can still enroll after your Initial Enrollment Period ends, but you will pay a late enrollment penalty on your Part A premium for as long as you have Medicare. Enroll as soon as possible to limit the penalty. Call 1-800-MEDICARE to discuss your situation and your options.

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.