Understanding The Medicare Annual Election Period (AEP)

Medicare AEP 2018

The AEP runs from October 15 to December 7 each year. If you didn’t sign up for one of these plans when you first became eligible for Medicare (during your Initial Enrollment Period), the AEP is generally your chance to make these changes, unless you qualify for a Special Election Period (SEP).

What changes can you make during the AEP?

Here’s a quick rundown of what you can do during the Annual Enrollment Period:

  • Change to a Medicare Advantage plan from Original Medicare, Part A and Part B.
  • Change from a Medicare Advantage plan to Original Medicare, Part A and Part B.
  • Change from one Medicare Advantage plan to another (regardless of whether either plan offers drug coverage).
  • Enroll in a Part D prescription drug plan.
  • Change from one Medicare prescription drug plan to another.
  • Opt out of Medicare prescription drug coverage completely.

Changes you make during the AEP go into effect January 1 of the next year.

Making changes after the Medicare AEP

Suppose you’re enrolled in a Medicare Advantage plan and you want to switch to Original Medicare, Part A and Part B. You can make this change during the Medicare Advantage Disenrollment Period, from January 1 to February 14 each year.

If you switch to Original Medicare during this period, you will have until February 14 to enroll in a Medicare Part D prescription drug plan. This coverage is optional, but if you wait until a future date to add it, you could pay a penalty for late enrollment (see below). Your coverage will begin the first day of the month after the plan gets your enrollment form.

Medicare allows changes outside the standard enrollment periods in specific situations that are often out of the beneficiary’s control, such as Medicare ending its contract with your plan, through Special Election Periods (SEPs). Other examples of these situations include, but are not limited to, the following:

  • Moving out of your plan’s service area.
  • Receiving both Medicare and Medicaid benefits.
  • Qualifying for Extra Help.
  • Living in, moving to, or moving from an institution such as a long-term care hospital or skilled nursing facility.

You could be charged a late-enrollment penalty (an amount that is added to your Medicare Part D premium for as long as you have this coverage) if all of the following are true:

  • You don’t enroll in a Medicare prescription drug plan (such as a stand-alone Medicare prescription drug plan or a Medicare Advantage plan that includes prescription drug coverage) when you’re first eligible.
  • You don’t have other creditable prescription drug coverage for 63 or more days in a row.
  • You then decide to enroll in a Medicare drug plan at a later date.


Question: What is the difference between Annual Election Period (AEP) and the Fall Open Enrollment season?
Answer: There is no difference.  Since 2005, a number of different terms have been used to describe the time each year when you can add, change, or drop your Medicare Part D or Medicare Advantage plan coverage.

So, depending on what you are reading, you might find the Medicare enrollment period starting October 15th and continuing through December 7th described as the:

  • AEP,
  • Annual Enrollment Period,
  • Annual Election Period,
  • Annual Coordinated Election Period,
  • OEP,
  • annual Open Enrollment Period,
  • Fall Open Enrollment season, or
  • Open Enrollment Period for Medicare Advantage and Medicare prescription drug coverage.

Again, the terms are all referring to the same enrollment period. The modern term used in the Medicare & You Handbook describing the annual enrollment period starting October 15th and continuing through December 7th is: “Open Enrollment”.

Based on CMS publications, we now use the term Medicare annual Open Enrollment Period interchangeably with AEP or Annual Enrollment Period or Annual Election Period or Annual Coordinated Election Period.