Table of Contents:

  1. What Is Medicare’s Annual Enrollment Period (AEP)?
  2. When Is Medicare’s Annual Enrollment Period?
  3. Who Qualifies for the Medicare Open Enrollment?
  4. How Can I Update My Coverage?
  5. When Do These Updates Take Effect?
  6. My Plan Isn’t What I Expected, What Can I Do?

What Is Medicare’s Annual Enrollment Period (AEP)?

Also known as Medicare’s annual open enrollment period, the Annual Enrollment Period (AEP) is the window of time during which current Medicare beneficiaries can update their coverage.

During this period, beneficiaries can: 

  • Select a Medicare Advantage plan
  • Switch from one Medicare Advantage plan to another
  • Switch from a Medicare Advantage plan to Original Medicare
  • Select a Medicare Part D plan
  • Switch from one Medicare Part D plan to another
  • Drop Medicare Part D coverage

When Is Medicare’s Annual Open Enrollment Period?

Each year, the AEP runs from October 15th to December 7th. Your provider will notify you of any changes to your current plan before the AEP begins through an Annual Notice of Change. If you are considering switching plans, watch out for updates from providers during the first half of October (all details are announced by October 15th).

Who Qualifies for Medicare Open Enrollment?

Any current Medicare beneficiary can make updates to their plan during the AEP. If you recently turned 65 or will turn 65 in 2021, you may not need to wait for the AEP because you qualify for an initial enrollment. Your initial enrollment period includes the seven months surrounding your birth month: the 3 months preceding your birthday, the month of your birthday, and the three months that follow. For example, if your birthday falls in April, you can sign up for Medicare any time from January 1st through July 31st.

When Do These Updates Take Effect?

Whether you sign up on October 15th or wait until December 7th, your new plan will take effect on January 1st of the following year. This begins the Medicare Advantage Disenrollment Period (MADP), which runs until February 14th. Beneficiaries who have enrolled in a new Medicare Advantage plan have the opportunity to switch back to Original Medicare during this period.

My Plan Isn’t What I Expected, What Can I Do? 

The Medicare Advantage Disenrollment Period runs from New Year’s Day through February 14th. During this window of time, Medicare beneficiaries have the right to disenroll from their Medicare Advantage plan if they’re not satisfied with their coverage. Once disenrolled, the beneficiary will be automatically re-enrolled in Original Medicare, and they do not have the option to choose a new Medicare Advantage plan until the next AEP begins in October. 

All Medicare Advantage beneficiaries also have access to an additional enrollment period. The Medicare Advantage Open Enrollment Period runs from January 1st through March 31st and enables beneficiaries to make the following changes:

  • Select a new Medicare Advantage plan
  • Switch back to Original Medicare and, if necessary, select a Part D Prescription Drug Plan

At any time of year, certain life-changing events such as divorce, the death of a spouse, or loss of employer-sponsored health insurance may trigger a Special Enrollment Period for eligible individuals.


Information adapted from the Centers for Medicare & Medicaid Services