Home » Medicare Eligibility and Enrollment » Annual Enrollment Period vs Open Enrollment Period

It’s easy to confuse Medicare enrollment periods, especially when they have similar names! We’re here to clear up the difference between the Annual Enrollment Period vs. Open Enrollment Period. Knowing the difference can help you determine when you can make changes to your Medicare plan in order to obtain the best benefits for your health and financial lifestyle.

mature senior women in early 60 hiking in autumn forest,

What is the Annual Enrollment Period (AEP)?

The Annual Enrollment Period is similar to the annual open enrollment period in the insurance marketplace, but in Medicare, the Open Enrollment Period is at the beginning of the year. To keep them straight, it’s helpful to know the windows of each enrollment period. The Annual Enrollment Period (AEP) runs from October 15 to December 7 each year. During this span of time, Medicare beneficiaries can make numerous changes to their coverage, including:

  • Switch from Original Medicare to a Medicare Advantage or add a Prescription Drug plan.
  • Switch from a Medicare Advantage plan to a different Medicare Advantage plan.
  • Switch from a Prescription Drug plan to a different Prescription Drug plan.
  • Drop (disenroll from) a Medicare Advantage or Prescription Drug plan and switch back to Original Medicare.

Medicare plan providers announce any updates or changes to their plans before the Medicare Annual Enrollment Period, so you can find up-to-date benefits and costs of a plan for the next year. This is called the Annual Notice of Change. When you receive your notice, you may find that certain benefits or costs have changed, and another plan may fit your needs better. The Annual Enrollment Period is the perfect opportunity to compare plans in your area and enroll in a plan that’s a better fit for your lifestyle.

Medicare Supplement Insurance (Medigap) plans are not in scope for AEP and have a different open enrollment period and there are different rules as to when someone may purchase a Medicare Supplement plan.

Are You Eligible for a Medicare Advantage Plan with Additional Benefits?
Get a Free Quote from a Licensed Insurance Agent.

What is the Open Enrollment Period (OEP)?

The Open Enrollment Period, also known as the Medicare Advantage Open Enrollment Period (MA OEP), runs from January 1 to March 31 each year. Unlike the Annual Enrollment Period, this enrollment period does not offer you the opportunity to make any changes to your Prescription Drug or Medicare Supplement Insurance (Medigap) plans. You can only make changes to your Medicare Advantage plan.

If you’re currently enrolled in a Medicare Advantage plan, you can use this timeframe to:

  • Switch to a different Medicare Advantage plan that better suits your needs
  • Drop (dis-enroll from) a Medicare Advantage plan and return to Original Medicare coverage only.

AEP vs. OEP: what’s the difference?

The Annual Enrollment Period allows you to make as many changes as you want to your plan throughout the enrollment period without penalty. In contrast, the annual Open Enrollment Period allows you to make a single change to your Medicare Advantage plan. You aren’t required to make changes to your plan during either period, but it is more common to make changes during the Annual Enrollment Period.

Essentially, if you decide that you’re unhappy with the choice you made during AEP after your coverage has begun, you can use OEP as a single chance to change your plan. Changes made during this time will go into effect on the first day of the month following the processing of your requested change. Whatever changes you decide to make during OEP will be final until the next Annual Enrollment Period with a few exceptions for qualifying life events that trigger a Special Enrollment Period. Because of this, having an agent you trust to make the process easy is essential!

Get Medicare Coverage that Fits Your Needs
Explore Medicare Advantage Plans In Your Area

Enrollment Eligibility

Medicare Annual Enrollment Period runs each year from October 15 to December 7. What is the Annual Enrollment Period vs. Open Enrollment Period?

Speak to a Licensed Insurance Agent Today

1-800-991-4407 / TTY 711

Mon-Fri 8am-9pm ET

Aetna® Anthem® Cigna Healthcare® Humana® UnitedHealthcare®

e-TeleQuote Insurance Inc. (“e-TeleQuote”), an affiliate of Primerica, Inc., does business as easyMed Insurance Services in all states other than New Mexico. e-TeleQuote is a duly licensed insurance agency appointed by Medicare Advantage HMO, PPO and PFFS plans and stand-alone prescription drug plans and insurance companies holding Medicare contracts approved by The Centers for Medicare & Medicaid Services (CMS). e-TeleQuote is not connected with or endorsed by the U.S. Government or the Federal Medicare Program. Enrollment in any plan for coverage is subject to insurance company approval. Enrollment in the plan depends on the plan’s contract renewal with Medicare. By using e-TeleQuote’s easyMedicare website, you understand and agree that in New Mexico, we operate as e-TeleQuote Insurance, Inc. (Your IP address and/or location coordinates may be gathered to verify your location.) Sales agents may be compensated based on your enrollment in a health plan. Medicare Supplement plans are not connected with or endorsed by the U.S. Government or the Federal Medicare program. e-TeleQuote complies with applicable Federal civil rights laws and does not discriminate on the basis of race, color, national origin, age, disability, sex, sexual orientation, gender identity, or religion. is a non-government site, powered by e-TeleQuote Insurance, Inc. e-TeleQuote provides a secure way to purchase Medicare insurance from the comfort of your home or workplace. We do not offer every plan available in your area. Currently we represent 5 organizations which offer 3,291 products in your area. Any information we provide is limited to those plans we do offer in your area. Please contact or 1-800-Medicare (TTY users should call 1-877-486-2048) 24 hours day/7 days a week, or your local State Health Insurance Program (SHIP), to get information on all of your options. Not all plans offer all of these benefits. Benefits may vary by carrier and location. Limitations and exclusions may apply. To send a complaint to Medicare, call 1-800-MEDICARE (TTY users should call 1- 877-486-2048), 24 hours a day/7 days a week). If your complaint involves a broker or agent, be sure to include the name of the person when filing your grievance.

Last Updated: October 13, 2023