Medicare Advantage Enrollment Guidance
What Is the Medicare Advantage Open Enrollment Period?
From January 1 through March 31, people already enrolled in Medicare Advantage generally have one opportunity to change their coverage.
When Is Medicare Advantage OEP?
January 1–March 31MA-OEP occurs every year immediately after the fall Annual Enrollment Period. It can provide a valuable second chance when a Medicare Advantage plan does not work as expected after the new coverage year begins.
A change made during MA-OEP generally becomes effective on the first day of the month after the new plan receives the enrollment request.
MA-OEP Is Not the Fall Annual Enrollment Period
The Medicare Annual Enrollment Period runs October 15 through December 7 and gives Medicare beneficiaries broader Medicare Advantage and Part D election options for January 1. MA-OEP is a narrower January 1–March 31 window only for people already enrolled in Medicare Advantage.
For a complete map of first-time and plan-change windows, use the Medicare Enrollment Periods hub. AEP and MA-OEP are also separate from the six-month Medigap Open Enrollment Period.
Who Can Use the Medicare Advantage OEP?
This enrollment period is specifically for people who are already enrolled in a Medicare Advantage plan on January 1. It does not provide a general enrollment opportunity for everyone with Medicare.
Your Prescriptions Are a Problem
A medication may not be covered as expected, may require prior authorization or may cost substantially more at your pharmacy.
Your Providers Are Out of Network
You may discover that a preferred doctor, specialist, hospital or healthcare system does not participate in your plan’s network.
Your Costs Are Higher Than Expected
Copayments, coinsurance, deductibles or other out-of-pocket expenses may not fit your healthcare needs or budget.
What Can—and Cannot—Be Done During OEP?
Medicare allows one MA-OEP change. Understanding exactly what this period permits can help prevent an enrollment mistake.
What You Can Do
- Switch from your current Medicare Advantage plan to a different Medicare Advantage plan.
- Leave Medicare Advantage and return to Original Medicare, consisting of Medicare Part A and Part B.
- Enroll in a standalone Medicare Part D prescription drug plan when returning to Original Medicare.
What You Cannot Do
- Join a Medicare Advantage plan for the first time if you currently have Original Medicare.
- Make repeated Medicare Advantage changes throughout the January through March window.
- Change from one standalone Part D plan to another solely because MA-OEP is occurring.
- Use MA-OEP if you are not currently enrolled in a Medicare Advantage plan.
Important: Returning to Original Medicare Does Not Guarantee Medigap
Leaving Medicare Advantage allows you to return to Original Medicare, but it does not automatically guarantee that you can purchase a Medicare Supplement, also called Medigap.
Unless you have a specific guaranteed-issue right, a Medicare Supplement insurance company may require medical underwriting and could decline your application or charge a different premium where permitted.
Before leaving Medicare Advantage, confirm whether you can obtain the supplemental coverage you want. Do not cancel existing coverage based only on an assumption that a Medigap application will be approved.
What Should You Review Before Changing Plans?
A lower premium or an attractive extra benefit does not necessarily mean a plan will provide the best overall fit. Review the coverage details that can materially affect your care and expenses.
Check Your Doctors and Hospitals
Confirm the exact plan network for your primary doctor, specialists, preferred hospitals and healthcare systems.
Review Every Prescription
Compare the formulary, drug tiers, pharmacy network, deductible, prior-authorization requirements and estimated annual costs.
Compare Medical Costs
Review copayments and coinsurance for office visits, specialists, diagnostic testing, outpatient procedures and hospital care.
Understand the Maximum Out-of-Pocket Limit
Consider the amount you could be responsible for during a high-use medical year—not only the plan’s monthly premium.
Check Important Plan Rules
Look for referrals, prior authorization, service-area restrictions and limits that may affect how you receive care.
Why the Medicare Advantage OEP Matters
Even a careful fall plan comparison cannot predict every issue that may appear after January 1. Provider networks can change, prescriptions can be processed differently than expected and real healthcare use can reveal costs or restrictions that were not obvious during enrollment.
MA-OEP acts as a limited safety net. It gives eligible Medicare Advantage members one opportunity to correct a poor fit instead of automatically remaining in the same plan for the rest of the year.
After March 31, many people must wait until another applicable enrollment period unless they qualify for a Medicare Special Enrollment Period.
Use These Guides Before Making the One OEP Change
Providers and facilities
Use the provider-network checklist to verify doctors, practice locations and hospitals for the exact plan.
Prescriptions and pharmacies
Use the Medicare Advantage prescription comparison to review formularies, restrictions and pharmacy pricing.
Total plan fit
Review the best Medicare Advantage fit and the broader annual plan review process before submitting a change.
If returning to Original Medicare is part of the plan, first review switching from Medicare Advantage to a Medicare Supplement, Medigap underwriting and any applicable guaranteed-issue rights. The election window does not itself guarantee Medigap acceptance.
Medicare Advantage OEP Questions
Can I use OEP if I currently have Original Medicare?
No. MA-OEP is for people already enrolled in a Medicare Advantage plan. It does not allow someone with Original Medicare to join Medicare Advantage for the first time.
How many times can I change plans during OEP?
Medicare generally permits one Medicare Advantage change during the January 1 through March 31 MA-OEP.
When will my new coverage begin?
A plan change made during MA-OEP generally begins on the first day of the month after the new plan receives your enrollment request.
Can I change only my standalone Part D plan during OEP?
Not solely because MA-OEP is taking place. MA-OEP allows an eligible person to enroll in standalone Part D when leaving Medicare Advantage and returning to Original Medicare.
Can I return to Original Medicare and buy a supplement?
You may return to Original Medicare during MA-OEP, but acceptance into a Medicare Supplement is not always guaranteed. Depending on your circumstances and state rules, you may need to pass medical underwriting unless you have a guaranteed-issue right.
Should I change plans just to receive additional benefits?
Additional benefits can be useful, but doctors, hospitals, prescriptions, medical costs and plan restrictions should be reviewed first. The value and availability of additional benefits vary by plan and location.
Independent Medicare guidance
Need Help Reviewing Your Medicare Advantage Plan?
I can help you compare the Medicare Advantage plans I represent using your actual doctors, hospitals, prescriptions, pharmacies, healthcare needs and financial priorities. There is no consultation fee and no obligation to change plans.
Learn more about Benjamin Thompson and Thompson Medicare Brokerage, or explore participating Medicare Advantage and Part D plans. Thompson Medicare Brokerage is not connected with or endorsed by the United States government or the federal Medicare program. The brokerage does not represent every Medicare organization or plan available in every area. Plan availability, benefits, premiums, provider networks, formularies and cost sharing vary by plan, county and coverage year. Medicare.gov and 1-800-MEDICARE provide information about all available Medicare Advantage and Part D options.