When You Can Enroll in Medicare

To enroll in Medicare, most people need to contact Social Security directly. It’s recommended you do this before your 65th birthday to avoid lapse in coverage and avoid any penalties for applying late. You should receive a packet in the mail from Medicare before you turn 65. You can enroll online, in person at the Social Security office, or by calling 800-772-1213.

You have a 7-month window around your 65th birthday to enroll; this is called your initial enrollment period. After that, you can still enroll in Medicare, but you may need to wait for a designated special/general enrollment period to do so. See below for details on the different enrollment periods.

  • This is the 7-month time frame surrounding the month of your 65th birthday.
  • You can start applying for Medicare three months before your birthday month. (For example, if your birthday is July 15, you can apply beginning April 1 and your coverage would start July 1.)
  • You can enroll in all four parts during this period.

This enrollment period applies:

  • If you choose to keep your existing employer-provided health insurance past your 65th birthday
  • 8 months after coverage for Parts A and B end
  • 63 days after coverage for Parts C and D end
  • If you missed the Initial or Special Enrollment periods, you can still sign up for Medicare Parts A and B during General Enrollment between Jan. 1 and March 31 each year.
  • If you apply for coverage during General Enrollment, it will take effect July 1 of that year. You may face higher premiums and possible fees for late enrollment.

This enrollment period runs from Oct. 15 to Dec. 7 each year.

  • This is for anyone who is eligible for Medicare and is the time when you can make changes to your coverage.
  • During this time, you can sign up for Parts C and D. You can also switch from Parts A and B (traditional Medicare) to Part C (Medicare Advantage), or from Part C to Parts A and B.
  • If you apply for coverage during Open Enrollment, it will take effect Jan. 1 of the following year.

This enrollment period is only for Medigap coverage.

  • It runs for 6 months and starts the month of your 65th birthday AND when you’ve signed up for Medicare Part B.
  • If you don’t sign up during open enrollment, other restrictions will apply.
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