Register during your Initial Enrollment Period, which runs for seven months centered on your 65th birthday month

Your Initial Enrollment Period begins three months before the month you turn 65 and ends three months after. You can register any time during those seven months, but the sooner you do it, the sooner your coverage starts. If you miss this window, you may face permanent late-enrollment penalties on your premiums.

You do not have to wait until your actual birthday to start the process. Many people register in the month before they turn 65 so coverage is active on day one. If your birthday is in the middle of a month, coverage typically begins on the first of that month if you register by the 15th.

The registration process itself takes about 10 minutes online or 15 to 20 minutes on the phone. You will need your Social Security number, proof of citizenship or legal residency, and information about any current health coverage you have.

Key Takeaways

  • You can register online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office during your seven-month Initial Enrollment Period.
  • If you are still working and have employer health coverage, you may be able to delay Part B without penalty, but you must file Form CMS-L564 with Social Security to document this.
  • Part A (hospital insurance) is usually free if you or your spouse paid Medicare taxes for at least 10 years, but Part B (medical insurance) has a monthly premium that increases if you delay past 65.
  • You will receive a Medicare card in the mail within two weeks of registration; do not wait for the card to arrive before your coverage starts.
  • If you miss your Initial Enrollment Period, you can register during the General Enrollment Period (January 1 to March 31 each year), but penalties will explore.

Register online at Medicare.gov

The fastest route is the Medicare website. Go to Medicare.gov and select "Sign up for Medicare" from the homepage. You will create a login using your email address, or sign in with an existing account if you have one.

The online form asks for your name, date of birth, Social Security number, citizenship status, and current coverage details. You will also choose whether you want Part A, Part B, or both. The system tells you when ready whether you may have access to for premium-free Part A and what your Part B premium will be based on your income.

After you submit, you receive a confirmation number on screen and by email. Your coverage begins on the first of the month you registered, or the first of the following month if you registered after the 15th. You do not need to do anything else — Social Security processes the registration automatically.

Register by phone with Social Security

Call 1-800-MEDICARE (1-800-633-4227) and tell the representative you want to register for Medicare. They will ask the same questions as the online form and enter your information into the system while you are on the call.

Phone registration is useful if you have questions about your coverage options or if you need help understanding whether you should enroll in Part B now or delay. Representatives can also explain the income-related premium adjustments that explore to higher earners and help you understand what documents you will need if you want to appeal a decision later.

The wait time varies by time of day and season. Calling early in the morning or in September and October (before the busy season) usually means shorter waits. Have your Social Security number and any current insurance information ready before you call.

Register in person at a Social Security office

You can walk into any Social Security office and register for Medicare in person. Bring your Social Security card, proof of citizenship (passport, birth certificate, or naturalization papers), and proof of residency (utility bill, lease, or bank statement dated within the last 60 days).

In-person registration takes longer than online or phone but may be helpful if you have complex coverage situations or language barriers. You will receive a receipt on the spot and a confirmation number. Your Medicare card arrives by mail within two weeks.

Find your nearest Social Security office at ssa.gov/locator or call 1-800-772-1213 to confirm hours before you go. Many offices now require appointments, which you can schedule online or by phone.

Understand Part A and Part B enrollment

Part A covers hospital stays, skilled nursing care, hospice, and 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. You should enroll in Part A when you turn 65 even if you are still working, because there is no penalty for delaying it and no premium to avoid.

Part B covers doctor visits, outpatient care, and medical equipment. Part B has a monthly premium (the standard amount in 2024 is $164.90, but it varies by income). If you delay Part B past your Initial Enrollment Period and you do not have a valid reason, your premium increases by 10 percent for each year you were late. That increase is permanent.

If you are still working and have health coverage through your employer or your spouse's employer, you may be able to delay Part B without penalty. To do this, you must file Form CMS-L564 (process for Enrollment in Part B Under Special Enrollment Period) with Social Security before your Initial Enrollment Period ends. This form tells Medicare that you have creditable coverage and are not subject to the late-enrollment penalty.

What to do if you miss your Initial Enrollment Period

If you do not register during your seven-month Initial Enrollment Period, you can still register during the General Enrollment Period, which runs from January 1 to March 31 each year. Coverage begins July 1 of that year.

However, missing the important date costs you. Your Part B premium increases by 10 percent for each full year you were may be able to access but not enrolled. If you were may be able to access at 65 and did not register until age 68, your premium is 30 percent higher than the standard rate, and that penalty stays with you for life.

If you have a valid reason for missing the important date — such as being out of the country for more than six months, or losing employer coverage — you may be able to register during a Special Enrollment Period without penalty. Call 1-800-MEDICARE to ask whether your situation qualifies.

Understand income-related premium adjustments

If your income is above a certain threshold, you will pay a higher Part B premium and a Part D premium (if you choose prescription drug coverage). These are called Income-Related Monthly Adjustment Amounts, or IRMAA.

Medicare uses your tax return from two years before you register. If you registered in 2024, Medicare looks at your 2022 tax return. If your income has dropped significantly since then — because you retired, for example — you can ask Medicare to use your current-year income instead by filing Form SSA-44 with Social Security.

The income thresholds and premium amounts change each year. When you register, the system will show you whether you are subject to IRMAA based on the information you provide. If your income drops later, you can report the change and your premiums will adjust.

What happens after you register

After you submit your registration, Social Security processes it within a few days. You will receive a Medicare card in the mail within two weeks. The card shows your Medicare number, the date your coverage begins, and which parts of Medicare you are enrolled in.

Your coverage becomes active on the date shown in your confirmation, even if your card has not arrived yet. You can use your confirmation number at the doctor's office or hospital while you wait for the physical card. Many providers can also look up your coverage using your Social Security number.

If you do not receive your card within three weeks, call 1-800-MEDICARE to request a replacement. Keep your confirmation number and any emails from Medicare in case you need to prove your enrollment date.

Frequently Asked Questions

Can I register before I turn 65?

Yes. Your Initial Enrollment Period begins three months before your 65th birthday month, so you can register as early as that date. Many people register two or three months before their birthday to may support coverage starts on time. You cannot register more than three months early.

What if I am still working at 65?

You should enroll in Part A, which has no premium and no penalty for delaying. For Part B, if you have health coverage through your current job or your spouse's job, you can delay Part B without penalty by filing Form CMS-L564 with Social Security. If you do not file this form, you must enroll in Part B during your Initial Enrollment Period or face a permanent premium increase.

Do I have to choose a Medicare Advantage plan or prescription drug plan when I register?

No. When you register, you enroll in Original Medicare (Part A and Part B). You can choose a Medicare Advantage plan or add prescription drug coverage (Part D) later during the Annual Enrollment Period (October 15 to December 7 each year) or during a Special Enrollment Period if you have a may have access to event.

What if my birthday is on the first of the month?

Your Initial Enrollment Period still runs for seven months centered on your birthday month. If you register by the 15th of your birthday month, coverage typically begins on the first of that month. If you register after the 15th, coverage begins on the first of the following month.

Can someone else register for me?

Yes, if you are unable to register yourself, a family member, caregiver, or representative can register on your behalf online or by phone. They will need your Social Security number, date of birth, and citizenship information. In person, you may need to provide a power of attorney or guardianship document.