Navigating the Medicare Advantage Open
Enrollment & the General Enrollment Period

Missed changes during Medicare Open Enrollment? You may still have options through Medicare Advantage Open Enrollment and the Medicare General Enrollment Period.

While the annual Medicare Open Enrollment period ended on December 7^th, Medicare decision-making doesn’t stop there. The early months of the year bring two additional enrollment opportunities that are just as important for certain beneficiaries:

• Medicare Advantage Open Enrollment Period (MA OEP)
• Medicare General Enrollment Period (GEP)

Understanding who these periods apply to — and what actions you can (and cannot) take is essential to avoiding coverage gaps, unexpected costs, or long-term penalties.

This guide focuses on three key areas:

• Understanding what changes are allowed during Medicare Advantage Open Enrollment
• Navigating the General Enrollment Period for Medicare Parts A and B
• Avoiding common mistakes that can lead to penalties or delayed coverage

Medicare Advantage Open Enrollment Period (MA OEP):

A Second Chance to Adjust Your Medicare Advantage Coverage

The Medicare Advantage Open Enrollment Period runs from January 1 through March 31 each year. This enrollment window is only available to individuals who are already enrolled in a Medicare Advantage (Part C) plan.

This period is designed to give beneficiaries a chance to make a correction if their Medicare Advantage plan is no longer meeting their needs.

What You Can Do During MA OEP:

• Switch from one Medicare Advantage plan to another Medicare Advantage plan
• Drop your Medicare Advantage plan and return to Original Medicare (Part A & Part B)
• Add a standalone Part D Prescription Drug Plan if you return to Original Medicare

What You Cannot Do During MA OEP:

• Switch from Original Medicare into a Medicare Advantage plan
• Enroll in Medicare Part D if you remain on Original Medicare and did not already have drug coverage
• Make multiple plan changes — you are limited to one change during this period

Important Considerations:

• Coverage changes take effect the first day of the month after your request is submitted
• If you return to Original Medicare and want a Medigap (Medicare Supplement) plan, acceptance is not guaranteed unless you qualify for a special right
• Provider networks, prescription drug formularies, and out-of-pocket costs should be carefully reviewed before making a change

This enrollment period is especially valuable if you discover your doctors are out-of-network, your prescriptions are more expensive than expected, or your plan’s costs have changed significantly.

The General Enrollment Period (GEP):

For Those Who Missed Their Initial Medicare Enrollment

The General Enrollment Period runs from January 1 through March 31 and applies to individuals who did not enroll in Medicare Part A and/or Part B when they were first eligible and do not qualify for a Special Enrollment Period.

Who Should Pay Attention to GEP?

• Individuals who delayed Medicare enrollment without having qualifying employer coverage
• Those who missed their Initial Enrollment Period (IEP)
• Beneficiaries who previously dropped Part B and now need to re-enroll

What Happens During GEP?

• You can enroll in Medicare Part A and/or Part B
• Coverage begins the first day of the month after you enroll
• Late enrollment penalties may apply, especially for Part B and Part D

Key Points to Understand:

• Part B penalties generally last for the rest of your life
• You typically cannot enroll in a Medicare Advantage or Part D plan until you have active Part A and Part B
• Once your Part A and Part B are active, you may qualify for a Special Enrollment Period to choose additional coverage

Because penalties and delayed coverage can have long-term financial consequences, it’s critical to understand your eligibility and options before enrolling.

Avoiding Common Enrollment Mistakes and Coverage Gaps

Both MA OEP and the GEP come with strict rules and limitations, making it easy to accidentally make a decision that leads to higher costs or reduced coverage.

Common Pitfalls to Avoid:

• Assuming MA OEP allows unlimited plan changes (it does not)
• Dropping Medicare Advantage without understanding Medigap underwriting rules
• Missing Part D enrollment after returning to Original Medicare
• Delaying Part B enrollment and triggering permanent penalties
• Enrolling without confirming prescription drug coverage or provider access

Pro Tip:

Medicare enrollment periods are not interchangeable. Each one serves a specific purpose, and using the wrong enrollment period — or missing one entirely — can have lasting consequences.

In Conclusion

The months of January through March offer important opportunities to correct, enroll, or adjust Medicare coverage — but only if you understand which enrollment period applies to your situation.

By:

• Using Medicare Advantage Open Enrollment wisely
• Enrolling in Part A and/or Part B during the General Enrollment Period if needed
• Avoiding costly mistakes and penalties

…you can move forward with confidence and clarity in your Medicare coverage.

If you need help determining which enrollment period applies to you, AZ SHIP is here to help. We provide free, unbiased Medicare counseling to help you understand your options and make informed decisions.

If you are ready for assistance with your Medicare Advantage review or need help enrolling during the General Enrollment Period, please complete the intake form below.