Medicare Annual Enrollment Period

What is the Medicare Annual Enrollment Period?

Medicare Enrollment Periods

Medicare has specific windows of time in which consumers are allowed to enroll in or switch plans. If you miss these windows, you may lose coverage or be subject to a fine. One window, called the Annual Enrollment Period, is the time in which you can change your Medicare coverage if you are already enrolled in Medicare. Read on to learn more about enrollment periods and the Annual Enrollment Period. 

The Enrollment Periods

There are 5 different enrollment periods. They are:

  • Initial Enrollment Period
  • Special Enrollment Period
  • General Enrollment Period
  • Annual Enrollment Period
  • Medicare Advantage/Open Enrollment Period

Below are each of the enrollment periods explained briefly in more detail.

Initial Enrollment

  • Target population: For people newly eligible for Medicare at 65
  • Time: A 7 month window – 3 months before your birthday month, your birthday month, and then the 3 months after your birthday month

Special Enrollment Period

  • Target Population: For people moving out of their plan’s service area or losing coverage because their plan no longer covers them
  • Time: A 2-3 month window surrounding the loss of coverage

General Enrollment Period

  • Target population: For people who missed the Initial Enrollment, this is the only other time they are allowed to enroll in Medicare
  • Time: January 1 – March 31st

Annual Enrollment Period

  • Target Population: For people who need to change coverage and are already enrolled in Medicare
  • Time: October 15 – December 7

Medicare Advantage/Open Enrollment Period: 

  • Target Population: For people who want to change Medicare Advantage plans, either to enroll or disenroll
  • Time: January 1 – March 31

Annual Enrollment Period

As stated above, the Annual Enrollment Period is the window of time in which people who already have Medicare can switch their plans. For example, if you had originally decided against enrolling in Part B but now wanted to enroll, you would do so during this time. The key difference between the Annual Enrollment Period is that this period is for people who are already enrolled in Medicare, not for people who are newly signing up. This window is from October 15th to December 7th.


While Medicare is flexible about its coverage options, it is quite strict about its enrollment periods. The Annual Enrollment Period is the period in which Medicare recipients can switch their plans. It is from October 15th to December 7th. If you miss this enrollment period, you are unable to switch your plan. To learn more about enrollment periods, contact us at Generations Insurance today.