What Is the Medicare Advantage Open Enrollment Period (OEP), and How Does It Work?

The Medicare Advantage Open Enrollment Period (OEP) gives people who are already enrolled in a Medicare Advantage (MA) plan a limited opportunity to make a one-time change to their coverage.

Understanding how OEP works can help you understand your coverage rules and timelines.

Medicare Advantage Open Enrollment Period: Key Dates

  • When: January 1 – March 31
  • Who it applies to: Individuals currently enrolled in a Medicare Advantage (Part C) plan

OEP does not apply to people who are only enrolled in Original Medicare.

What You Can Do During Medicare Advantage OEP

If you are currently enrolled in a Medicare Advantage plan, you may make one of the following changes during OEP:

  • Switch to another Medicare Advantage plan
     (with or without prescription drug coverage)
  • Drop your Medicare Advantage plan and return to Original Medicare
     If you do this, you may also enroll in a standalone Medicare Part D prescription drug plan

Important: You may only make one change during OEP. If you submit multiple requests, the last election made during the OEP window is the one that counts.

Coverage changes generally take effect the first day of the month after your request is made.

What You Cannot Do During OEP

The Medicare Advantage Open Enrollment Period has important limitations.

You cannot:

  • Join a Medicare Advantage plan if you are currently in Original Medicare
  • Make changes if you are not already enrolled in an MA plan

If you are in Original Medicare and want to join a Medicare Advantage plan, you typically must wait for:

  • Fall Open Enrollment: October 15 – December 7

Or qualify for a Special Enrollment Period (SEP) due to certain life events

How to Get Unbiased Medicare Guidance

For official, unbiased help understanding Medicare rules and coverage options, these trusted resources are recommended:

  • Medicare.gov or 1-800-MEDICARE
    Get official information about eligibility, deadlines, and coverage options.
  • State Health Insurance Assistance Program (SHIP)
    SHIP provides free, local, unbiased Medicare counseling.
    You can find your state’s program at SHIPhelp.org
    (Example: Florida’s SHIP program is SHINE.)

How Our Clinic Fits Into Your Medicare Coverage (Informational)

Our role is to serve as your primary care team — regardless of your specific Medicare Advantage plan.

We help patients with:

  • Primary care and wellness visits
  • Chronic condition management
  • Preventive screenings
  • Care coordination and referrals

If you have questions about how your current plan works with care at our clinic — such as copays, referrals, or medication reviews — our team can explain what to expect at your appointments.

This information is educational only and does not include plan selection or enrollment advice.

Frequently Asked Questions About Medicare Advantage OEP

Does OEP affect when my new coverage starts?
Yes. Changes made during OEP generally take effect on the first day of the following month.
Can I make multiple changes during OEP?
No. You are allowed one opportunity to make a change. If more than one election is submitted, the last one made is the one that takes effect.
Is OEP the same as Fall Open Enrollment?
No.
Fall Open Enrollment (Oct 15–Dec 7): Allows many people to join, drop, or switch Medicare Advantage or Part D plans.
OEP (Jan 1–Mar 31): Only applies to people already enrolled in a Medicare Advantage plan.

 

Compliance Notice

This article is for educational purposes only and does not encourage or recommend plan changes. For official Medicare enrollment guidance, visit Medicare.gov or call 1-800-MEDICARE. For free, unbiased counseling, contact your local SHIP program.

What is the Medicare Advantage Open Enrollment Period (OEP)?
The Medicare Advantage Open Enrollment Period (OEP) runs from January 1 to March 31 and applies only to people who are already enrolled in a Medicare Advantage (Part C) plan. During OEP, eligible individuals have a one-time option to change their coverage.
Who can use Medicare Advantage OEP?
OEP applies to people who are currently enrolled in a Medicare Advantage plan. If you are enrolled in Original Medicare only, OEP does not allow you to join a Medicare Advantage plan.
What changes can I make during Medicare Advantage OEP?
If you are currently in a Medicare Advantage plan, you can switch to another Medicare Advantage plan (with or without drug coverage) or drop your Medicare Advantage plan and return to Original Medicare. If you return to Original Medicare, you may also enroll in a standalone Part D prescription drug plan.
Can I make multiple changes during OEP?
You can make only one change during OEP. If multiple elections are submitted during the period, the last election made is the one that takes effect.
When do OEP changes take effect?
Medicare.gov or call 1-800-MEDICARE. You can also contact your State Health Insurance Assistance Program (SHIP) for free, local, unbiased counseling.