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When Can You Sign Up for Medicare Part A and Part B? - Medicare and You Handbook - A Guide to Medicare


When Can You Sign Up for Medicare Part A and Part B?

 Enrollment Periods:


Initial Enrollment Period

You can sign up when you’re first eligible for Part A and/or Part B (for which you pay monthly Premiums) during your Initial Enrollment Period. For example, if you’re eligible when you turn 65, you can sign up during the 7-month period that begins 3 months before the month you turn 65, includes the month you turn 65, and ends 3 months after the month you turn 65.

3 months before the month you turn 65 2 months before the month you turn 65 1 month before the month you turn 65 The month you turn 65 1 month after the month you turn 65 2 months after the month you turn 65 3 months after the month you turn 65
Sign up early to avoid a delay in coverage. To get Part A and/or Part B the month you turn 65, you must sign up during the first 3 months before the month you turn 65. If you wait until the last 4 months of your Initial Enrollment Period to sign up for Part A and/or Part B, your coverage will be delayed. See chart below.


Note: If you’re automatically enrolled, these enrollment periods don’t apply to you.

If you sign up for Part A and/or Part B during the first 3 months of your Initial Enrollment Period, your coverage start date will depend on your birthday:
  • If your birthday isn’t on the first day of the month, your Part B coverage starts the first day of your birthday month. For example, Mr. Green’s 65th birthday is July 20, 2026. If he enrolls in April, May, or June, his coverage will start on July 1, 2026.
  • If your birthday is on the first day of the month, your coverage will start the first day of the prior month. For example, Mr. Kim’s 65th birthday is July 1, 2026. If he enrolls in March, April, or May, his coverage will start on June 1, 2026. So, If your birthday is on the first day of the month, you will need to use the month before your birthday as "the month you turn 65." when reading the chart above.

If you enroll in Part A and/or Part B the month you turn 65 or during the last 3 months of your Initial Enrollment Period, your start date will be delayed:
If you enroll in this month of your initial enrollment period: Your coverage starts:
The month you turn 65 1 month after enrollment
1 month after you turn 65 2 months after enrollment
2 months after you turn 65 3 months after enrollment
3 months after you turn 65 3 months after enrollment




General Enrollment Period

If you didn’t sign up for Part A and/or Part B (for which you pay monthly Premiums) when you were first eligible, you can sign up between January 1–March 31 each year. Your coverage will begin July 1. You may have to pay a higher premium for late enrollment. See: What You Pay for Medicare:


If you sign up during these months: Your coverage will begin on:
January July 1
February July 1
March July 1





Special Enrollment Period

If you didn’t sign up for Part A and/or Part B (for which you pay monthly Premiums) when you were first eligible because you’re covered under a group health plan based on current employment, you can sign up for Part A and/or Part B as follows:

Anytime that you or your spouse (or family member if you’re disabled) is working, and you’re covered by a group health plan through the employer or union based on that work       Or      During the 8-month period that begins the month after the employment ends or the group health plan insurance based on current employment ends, whichever happens first


Usually, you don’t pay a late enrollment penalty if you sign up during a Special Enrollment Period. This Special Enrollment Period doesn’t apply to people with End-Stage Renal Disease (ESRD). You may also qualify for a Special Enrollment Period if you’re a volunteer serving in a foreign country.

Note: COBRA and retiree health plans aren’t considered coverage based on current employent. You’re not eligible for a Special Enrollment Period when that coverage ends. To avoid paying a higher premium, make sure you sign up for Medicare when you’re first eligible.




This website also offers a wealth of information regarding Medicare Part D and Medicare Advantage plans.



(Primary Source: Centers for Medicare and Medicaid Services - Medicare and You Handbook. This content may have been enhanced by this site to include further examples, explanations, and links.)