Medicare OEP Open Enrollment Period
The Medicare Open Enrollment Period (OEP) runs annually from January 1 to March 31. It is specifically for individuals already enrolled in a Medicare Advantage (Part C) plan as of January 1.
This period does not apply to those with Original Medicare (Part A and B) only; it’s strictly for Medicare Advantage plan members who may want to make a one-time change.
What Changes Can You Make During OEP
Those enrolled in a Medicare Advantage plan, can make one change during the OEP. The options include:
- Switching to a different Medicare Advantage plan, with or without drug coverage
- Dropping your Medicare Advantage plan and returning to Original Medicare, with the option to add a Part D prescription drug plan
Changes You Cannot Make:
- Switch from Original Medicare to a Medicare Advantage plan
- Enroll in Part D drug coverage if you’re on Original Medicare and missed your IEP or AEP
- Make multiple changes; OEP only allows one switch
Watch a video on Medicare enrollment periods
Why Use the OEP
Here are a few common reasons beneficiaries take advantage of the Medicare OEP:
- Their current Medicare Advantage plan doesn’t cover a needed medication or provider
- They discovered higher costs or restrictions after using the plan in January
- They had a change in health and want a different plan with better specialist coverage
- They were unaware of better plan options during the Annual Enrollment Period (AEP), which runs from October 15 to December 7
How Is OEP Different from AEP
| Feature | AEP (Oct 15–Dec 7) | OEP (Jan 1–Mar 31) |
|---|---|---|
| Who Can Use It | All Medicare beneficiaries | Only those enrolled in Medicare Advantage |
| Number of Changes | Multiple changes allowed | One change allowed |
| Types of Changes | Switch plans, join/drop Part D, switch to/from Medicare Advantage or Original Medicare | Switch Medicare Advantage plans or drop MA to return to Original Medicare |
Important Considerations
- If you switch to Original Medicare during OEP, you may not be guaranteed Medigap (Medicare Supplement) coverage; unless you’re in a trial right or qualify for a Special Enrollment Period.
- Any changes made during the OEP become effective the first day of the month after the change is made (e.g., a change in February takes effect March 1).
- It’s important to review coverage early in the year to determine if your current plan still meets your needs.
Work with a Licensed Agent
The Medicare OEP is a valuable but limited opportunity to make corrections or improvements to your coverage. If you’re unsure whether your plan fits your health needs or budget, speak with a licensed Medicare agent. They can help you compare options, check provider networks and drug formularies, and make confident decisions about your healthcare.