Medicare registration opens three months before you turn 65

You can register for Medicare starting on the first day of the three-month period before your 65th birthday. If you turn 65 on June 15, your registration window opens on March 1. You do not have to wait until your actual birthday — you can sign up as soon as that window opens, and coverage can start as early as the first day of the month you turn 65.

The registration period lasts seven months total: the three months before you turn 65, the month you turn 65, and the three months after. During this time, you can register without penalty. If you miss this window, you may face a permanent increase to your premiums.

Key Takeaways

  • Registration opens three months before your 65th birthday and stays open for seven months total.
  • You can register online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
  • If you delay registration past the seven-month window, you will pay a higher premium for Part B and Part D for as long as you have Medicare.
  • You do not need to register if you are already receiving Social Security benefits — Medicare will enroll you automatically.
  • If you are still working and have health coverage through your employer, you may be able to delay Part B registration without penalty.

What happens if you register late

Missing your registration window triggers a late enrollment penalty that increases your monthly premium. For Part B, the penalty is 10 percent of the standard premium for each full 12-month period you were not registered. For Part D (prescription drug coverage), the penalty is 1 percent of the national average premium for each month you were not registered. These penalties are permanent — they do not go away after a certain time.

The only exception is if you had creditable coverage — health insurance through your employer or a spouse's employer that was at least as good as Medicare. If you can show you had creditable coverage when you turned 65, you can register late without penalty. You will need documentation from your employer or insurance company proving the coverage dates and that it was creditable.

How to register for Medicare

You have three ways to register. The fastest is online at Medicare.gov — you can complete the process in about 10 minutes if you have your Social Security number and information about any current health coverage. You will need to create a Medicare.gov account first.

You can also call 1-800-MEDICARE (1-800-633-4227). Representatives are available Monday through Friday, 8 a.m. to 8 p.m. Eastern time. Have your Social Security number and birth date ready. The call usually takes 15 to 20 minutes.

A third option is to visit your local Social Security office in person. You can find the nearest office at ssa.gov/locator. Bring your Social Security card, birth certificate, and proof of citizenship or legal residency. This route takes longer because you need an appointment, but some people prefer handling it face-to-face.

Automatic enrollment if you receive Social Security

If you are already receiving Social Security retirement or disability benefits when you turn 65, Medicare will enroll you automatically. You do not need to do anything. Your Medicare card will arrive in the mail about two weeks before your coverage starts on the first day of your birth month.

Even though enrollment is automatic, you should still review your coverage choices. Medicare Part A (hospital insurance) and Part B (medical insurance) are automatic, but you need to choose a Part D plan (prescription drug coverage) if you take medications. If you do not choose a plan during your registration window, you will be assigned a default plan, which may not cover your specific drugs.

Delaying Part B if you have employer coverage

If you are still working and have health insurance through your job or your spouse's job, you can delay registering for Part B without penalty. This is called the Special Enrollment Period. You must register within eight months after your employment ends or your employer coverage stops, whichever comes first.

To use this exception, your employer coverage must be based on current employment — not retiree coverage. You will need to show proof that you had this coverage when you turned 65. Keep your insurance cards and any letters from your employer stating the coverage dates. When you do register for Part B later, bring this documentation with you or have it ready if you register online.

What Medicare covers and when it starts

Medicare has four parts. Part A covers hospital stays, skilled nursing facility care, and hospice. Part B covers doctor visits, outpatient care, and medical equipment. Part D covers prescription drugs. Part C, also called Medicare Advantage, is an alternative to Parts A and B offered by private insurance companies.

If you register during your initial seven-month window, coverage can start as early as the first day of the month you turn 65. If you register after that window closes, coverage starts the first day of the month after you register. The longer you wait, the longer you go without coverage and the higher your permanent penalty becomes.

Documents you will need to register

Have these items ready before you register, whether online, by phone, or in person:

  • Your Social Security number
  • Your birth date
  • Proof of U.S. citizenship or legal residency (birth certificate, passport, or naturalization papers)
  • Information about any current health coverage, including policy numbers and employer name
  • If you have worked recently, your most recent tax return or W-2

If you are registering in person at a Social Security office, bring the originals or certified copies of these documents. If you are registering online or by phone, you can have them nearby but will not need to submit them when ready — Social Security will verify them in their system.

Frequently Asked Questions

Can I register before the three-month window opens?

No. Medicare.gov, the phone line, and Social Security offices will not accept your registration before the first day of the three-month period before your 65th birthday. If you try to register early, you will be asked to call back or return during the correct window.

What if I turn 65 and I am not a U.S. citizen?

You can register for Medicare if you are a lawful permanent resident (green card holder) and have lived in the United States for at least five years. You will need to show your green card and proof of residency. Some non-citizens do not meet these requirements and cannot register; Social Security will tell you during the registration process if you are ineligible.

Do I have to choose a Medicare Advantage plan or can I stick with Original Medicare?

You can choose either. Original Medicare (Parts A and B) is run by the federal government. Medicare Advantage (Part C) is run by private insurance companies and often includes Part D. Both are valid choices. If you choose Original Medicare, you must separately choose a Part D plan for prescriptions. You can change your choice each year during the annual enrollment period.

What if I miss the important date by just a few days?

The important date is firm. If your seven-month window closes on a specific date and you register the day after, you have missed the window and will owe a late enrollment penalty. There is no grace period. If you are close to the important date, register when ready by phone or online rather than waiting.

Can my spouse register for me?

No. You must register yourself, either online, by phone, or in person. Your spouse can help you gather documents and be present during the process, but Social Security requires you to provide your own information and confirm your identity.