What Is the Medicare Advantage Open Enrollment Period and Who Can Use It?

Medicare Advantage Open Enrollment runs Jan 1-Mar 31. Learn who qualifies, what changes you can make, and what to watch out for before the deadline.

Author: Lynsey Brennan, Licensed Medicare Advisor | Published July 30, 2026 Reading time: 6 min read

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Quick Answer

The Medicare Advantage Open Enrollment Period (MA OEP) runs every year from January 1 through March 31. If you're already enrolled in a Medicare Advantage plan, you can use this window to switch to a different Medicare Advantage plan or drop your Advantage plan and return to Original Medicare (with the option to add a Part D drug plan). Only people already in a Medicare Advantage plan on January 1 can use this period — it is not available to people on Original Medicare.

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Key Takeaways

• The MA OEP runs January 1 - March 31 each year and is only for people already enrolled in Medicare Advantage.
• You can make one switch during this period — not multiple changes.
• Dropping your Medicare Advantage plan returns you to Original Medicare, but getting a Medicare Supplement (Medigap) plan may require medical underwriting in Florida.
• Florida's Medicare Advantage enrollment rate is 56.1% (CMS Medicare Monthly Enrollment, 2024) — higher than the national average of about 54% (CMS, 2024).
• Not sure which direction to go? Use our plan comparison tool to review your options side by side.

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Table of Contents

1. What Is the MA OEP? 2. Who Can Use It — and Who Cannot 3. What Changes You Can and Cannot Make 4. Why This Matters Especially in Florida 5. The Medigap Problem Nobody Warns You About 6. How to Decide Whether to Switch 7. Frequently Asked Questions

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What Is the MA OEP? {#what-is-the-ma-oep}

The Medicare Advantage Open Enrollment Period is a federally defined window — January 1 through March 31 — during which people already enrolled in a Medicare Advantage plan can make one plan change. CMS established this period so that people who enrolled during the fall Annual Enrollment Period (AEP) and later realized the plan wasn't right for them would have an early opportunity to correct that.

It replaced an older structure and has been in its current form since 2019. The key word is already — you have to be in a Medicare Advantage plan when the period opens on January 1 to use it. People who enrolled in a new Advantage plan during AEP and find their new plan starts poorly (wrong formulary, a hospital not in network) often use the MA OEP to make a correction.

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Who Can Use It — and Who Cannot {#who-can-use-it}

You can use the MA OEP if:

• You are enrolled in any Medicare Advantage plan (with or without drug coverage) on January 1 of the current year.
• You want to switch to a different Medicare Advantage plan.
• You want to drop Medicare Advantage entirely and return to Original Medicare Parts A and B.

You cannot use the MA OEP if:

• You are on Original Medicare only (Parts A and B, with or without a standalone Part D plan).
• You have a Medicare Supplement (Medigap) policy and want to add or change Advantage coverage — the MA OEP does not apply to you.
• You already made your one change for this period.

This is a common point of confusion. The MA OEP is often lumped together with other enrollment periods, but it is a separate and more limited window. For a full picture of when you can make changes, see our Medicare enrollment periods guide.

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What Changes You Can and Cannot Make {#what-changes-you-can-make}

During the MA OEP, you get one election change. Here is what that can include:

• Switch from one Medicare Advantage plan to a different Medicare Advantage plan (for example, from an HMO to a PPO, or from a plan with a high deductible to one with lower cost-sharing).
• Drop your Medicare Advantage plan and return to Original Medicare — and, if you do, you can also join a standalone Part D drug plan at the same time.

What you cannot do during the MA OEP:

• Switch from Original Medicare to a Medicare Advantage plan.
• Make more than one plan change.
• Enroll in a standalone Part D plan if you stay in Medicare Advantage (drug coverage is typically bundled in MA-PD plans).

One practical note on Part D: starting in 2025, the out-of-pocket cap for Part D drug costs is $2,000 per year (Inflation Reduction Act). Covered insulin is also capped at $35 per month under Medicare Part D. If your current plan's formulary doesn't cover your medications well, the MA OEP may be the right moment to switch to a plan with better drug coverage. Learn more in our Part D drug coverage guide.

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Why This Matters Especially in Florida {#florida-angle}

Florida has one of the most competitive Medicare Advantage markets in the country. According to CMS Medicare Monthly Enrollment data (2024), 56.1% of Florida Medicare beneficiaries are enrolled in Medicare Advantage — above the national average of roughly 54% (CMS, 2024). That means more Florida residents are directly affected by this enrollment period than in most other states.

South Florida in particular — including Palm Beach, Broward, and Miami-Dade counties — tends to have a large number of plan options from carriers like Humana, UnitedHealthcare, Aetna, and Devoted Health, among others. More choices is generally good, but it also means more complexity. Plan networks, formularies, and extra benefits can vary significantly even between two plans from the same insurer. For a closer look at how Florida stacks up, see our Florida Medicare data page.

Also worth knowing: the 2026 Medicare Advantage out-of-pocket maximum cap for in-network services is $9,350 (CMS, 2025). Individual plan maximums can be set lower than that cap, so comparing this figure across plans is one of the most important things to check before you switch.

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The Medigap Problem Nobody Warns You About {#medigap-problem}

Here is something that catches people off guard. If you drop your Medicare Advantage plan during the MA OEP and return to Original Medicare, you do not automatically have the right to buy a Medigap policy in Florida. In most states — Florida included — Medigap insurers can use medical underwriting outside of guaranteed issue periods. That means they can charge you more or decline to cover you based on your health history.

There are some exceptions (certain Special Enrollment Rights), but they are narrow. If you are thinking about going back to Original Medicare and adding a Medigap plan to fill the gaps, please talk to a licensed Medicare advisor before making that change. Returning to Original Medicare without Medigap coverage means you are exposed to significant cost-sharing with no annual cap. Our Medicare Advantage vs. Supplement comparison breaks down these trade-offs in plain terms.

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How to Decide Whether to Switch {#how-to-decide}

Ask yourself these questions before making any change:

1. Are my doctors still in-network? Provider networks can change year to year. Confirm your physicians and specialists accept your plan for the current year. 2. Are my medications still covered at an affordable tier? Pull up the plan's formulary and check your specific drugs. 3. What is the plan's out-of-pocket maximum? Remember, the federal cap for 2026 is $9,350 in-network (CMS, 2025), but some plans set it lower. 4. Am I using the extra benefits the plan offers? Dental, vision, and hearing benefits vary widely by plan. If you are not using them, they may not be worth a higher premium. 5. Would Original Medicare with a Medigap plan fit my situation better? See our Medicare Advantage vs. Supplement guide for an honest look at both sides.

If you want to compare specific plans available in your zip code, our plan comparison tool can help you look at options side by side. You can also review current 2026 Medicare costs to understand what baseline expenses look like under Original Medicare (Part B premium: $185/month; Part B deductible: $257, per CMS, November 2025).

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Frequently Asked Questions {#frequently-asked-questions}

Q: Can I switch from Original Medicare to Medicare Advantage during the MA OEP? A: No. The MA OEP is only available to people who are already enrolled in a Medicare Advantage plan on January 1. If you are on Original Medicare and want to switch to Advantage, you would typically need to wait for the Annual Enrollment Period (October 15 - December 7) unless you qualify for a Special Enrollment Period.

Q: If I switch Medicare Advantage plans during the MA OEP, when does my new coverage start? A: Your new coverage typically begins on the first day of the month after your plan receives your enrollment request. If you enroll in February, for example, your new plan would generally start March 1.

Q: Does the MA OEP affect my Part D drug coverage? A: If you switch to a different Medicare Advantage plan that includes drug coverage (an MA-PD plan), your drug coverage changes with the plan. If you drop Medicare Advantage and return to Original Medicare, you can join a standalone Part D plan at the same time to maintain drug coverage.

Q: I'm in Florida and thinking about dropping my Advantage plan. Do I automatically qualify for Medigap? A: Not automatically. Florida follows standard federal Medigap rules, which means outside of guaranteed issue periods, insurers can use medical underwriting. Before dropping your Advantage plan, speak with a licensed Medicare advisor to understand your Medigap options and any timing considerations that could affect your eligibility.

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The Bottom Line

The Medicare Advantage Open Enrollment Period — January 1 through March 31 — gives current Advantage enrollees one meaningful chance each year to correct a plan that isn't working. It is a limited window with specific rules, and the consequences of making the wrong move (especially around Medigap eligibility) can follow you for years. If you are in Florida and unsure whether your current plan still fits your needs, a no-cost Medicare plan review can help you sort through your options before the deadline.

Schedule a free Medicare review at HealthPlan Connect — or call Lynsey Brennan directly at 561-247-0678. There is no obligation, and you will get straight answers from a licensed Medicare advisor who knows the Florida market.

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Sources

• CMS Medicare Monthly Enrollment, 2024 — Florida and national Medicare Advantage enrollment figures
• CMS, November 2025 — 2026 Part B premium ($185/month) and Part B deductible ($257)
• CMS, 2025 — 2026 Medicare Advantage in-network out-of-pocket maximum cap ($9,350)
• Inflation Reduction Act (IRA) — Part D out-of-pocket cap ($2,000/year starting 2025); insulin cap ($35/month)
• CMS Medicare Advantage Open Enrollment Period regulations (42 CFR § 422.62)

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This article is for educational purposes and is not affiliated with or endorsed by the federal Medicare program or any government agency. HealthPlan Connect is a private, licensed Medicare advisory service. FL License #G007269.