You can only join, switch, or cancel Medicare coverage at certain times throughout the year. AEP happens every year from October 15 to December 7.

During this time, you can change your coverage to best meet your needs for the upcoming year. These changes will go into effect on January 1.

If the provider of your current plan has made changes that affect things like cost and coverage, they’ll send you an annual notice of change (ANOC). You’ll typically receive this by mail sometime in September.

Information about the different Medicare health and drug plans for the upcoming year will become available beginning in October. This gives you time to review and compare different plans before AEP begins on October 15.

You may have heard the terms “annual enrollment period” and “open enrollment period” used interchangeably.

While the media, public, and insurance companies often use the term AEP, both Medicare and the Centers for Medicare & Medicaid Services (CMS) refer to this time frame as Medicare’s “open enrollment period.”

Most of the time, AEP and Medicare open enrollment refer to the same time frame.

The difference in terminology is likely to avoid confusion between AEP and the separate open enrollment periods for Medicare Advantage (Part C) and Medigap, which occur at other times during the year.

Each year, private insurance companies that offer Medicare Advantage or prescription drug (Part D) plans can make changes to the policies that they offer. These changes can affect things like:

  • the cost of your plan
  • what’s covered under your plan
  • which healthcare providers and pharmacies are considered “in-network” for your plan

Because of this, your current health or drug plan may no longer be a good fit for your needs for the coming year. During AEP, you can select a different health or drug plan for the next year that works better for you.

During AEP, you can:

  • switch from Original Medicare to a Medicare Advantage plan
  • switch from a Medicare Advantage plan to Original Medicare
  • switch to a different Medicare Advantage plan
  • switch from a Medicare Advantage plan that includes prescription drug coverage to one that does not
  • switch from a Medicare Advantage plan that doesn’t include prescription drug coverage to one that does
  • join, switch, or drop a prescription drug plan

You may be eligible to make changes during other enrollment periods, but there are often certain criteria that must be met.

General enrollment period

From January 1 to March 31, you can:

  • enroll in Part A and/or Part B if you didn’t do so when you were first eligible
  • join a Medicare Advantage plan if you have Part A coverage and get Part B coverage for the first time during this enrollment period

If you make changes during this period, your coverage will start on July 1. You may have to pay a late enrollment penalty.

Medicare Advantage OEP

From January 1 to March 31, you can:

  • switch to a different Medicare Advantage plan (with or without prescription drug coverage)
  • switch from a Medicare Advantage plan to Original Medicare
  • enroll in a Part D plan if you’re switching to Original Medicare

You may only make one change during this enrollment period. Your changes will go into effect the first month after the provider receives your change request.

Part D enrollment (special circumstances)

From April 1 through June 30, you can enroll in a Part D plan if both of the following are true:

  • you have to pay a premium for Part A
  • you first enrolled in Part B during the general enrollment period

If you enroll in a Part D plan during this time frame, your prescription drug coverage will begin on July 1. It’s possible that you’ll have to pay a late enrollment penalty on your Part D premium for enrolling late.

Medigap OEP

Medigap, also called Medicare supplement insurance, helps cover some of the out-of-pocket costs associated with Original Medicare.

The Medigap OEP lasts for 6 months. It begins when both of the following are true:

  • you’re age 65 or older
  • you’ve enrolled in Part B for the first time

Medigap can only be used with Original Medicare. If you have a Medicare Advantage plan, you cannot enroll in Medigap.

Special enrollment periods (SEP)

Sometimes you can make changes to your Medicare plans outside of the enrollment periods discussed above.

You’re eligible for a SEP if you didn’t sign up for Medicare when you were first eligible because you were covered under an employer-provided plan. This includes coverage under a spouse or family member’s plan.

You can enroll in Medicare anytime you’re still covered by this plan or in the 8-month period after employer-provided coverage ends. If you enroll during a SEP, you typically don’t pay late enrollment penalties.

There are also SEP associated with Medicare Advantage and Part D plans. These periods are triggered by changes to your current plan or life events like moving, marriage, or divorce.

These are just a few examples of when you can change your Medicare health or drug plan in a SEP. The length of a SEP and the type of changes you can make may vary based on your situation.

Medicare’s AEP occurs in the fall of each year, from October 15 to December 7. During AEP, you can make changes to your Medicare health and drug plans. These changes will be effective beginning on the first day of the new year.

You may choose to make changes to your plan because it no longer suits your needs or will cost more in the upcoming year. If your plan is making changes that impact its cost or coverage, you’ll be notified before AEP begins.

It’s always important to review your plan each year, comparing it to others that are available in your area. If you have additional questions or concerns, you can contact Medicare, a specific plan’s provider, or your local SHIP office for help.