What is the Medicare Advantage Open Enrollment Period?

Medicare Advantage Open Enrollment runs January 1 through March 31. It is only for people already in an Advantage plan, and it allows one change.

Updated September 3, 2026 · 3 min read · by Gerino Alejos

Key points

Medicare Advantage Open Enrollment runs January 1 through March 31, and only for people already in an Advantage plan on January 1.
You can switch to a different Advantage plan, or drop yours and go back to Original Medicare with a drug plan.
Before dropping an Advantage plan, make sure you can still buy a Medigap policy, the coverage that pays the share Medicare leaves you.

Medicare Advantage Open Enrollment runs January 1 through March 31 every year. It is a correction window for people who started January in an Advantage plan and found it was not what they expected. An Advantage plan is private coverage that replaces Original Medicare, the coverage run by the government.

Who can use it

Only people who are already in a Medicare Advantage plan on January 1. That is the whole rule. It does nothing for anyone else, which is where the confusion starts.

What it lets you do

Two moves are allowed, and you may make one.

Switch from your Advantage plan to a different Advantage plan.
Drop your Advantage plan, go back to Original Medicare, and add a standalone Part D plan, a drug plan you buy on its own.

What it does not let you do

Move from Original Medicare into an Advantage plan. It does not work in that direction.
Join a Part D plan if you are on Original Medicare and do not have one.
Switch from one standalone Part D plan to another.
Make a second change. You get one, and it is done.

The one change limit catches people. If you switch plans in January and dislike the new one in February, you generally wait until October. Use the window on a decision you have already made.

When your change takes effect

Your new coverage starts the first day of the month after the plan receives your request. Make a change in February and coverage starts March 1. See the enrollment steps.

The Medigap problem: no guaranteed issue

If you use this window to go back to Original Medicare, you will want a supplement, a Medigap policy that pays the 20 percent Medicare leaves you. On a $50,000 hospital bill, that is $10,000 out of your pocket. Whether you can buy one depends on whether a protected window is still open.

One of those is the trial right. If you joined an Advantage plan when you first became eligible for Medicare at 65, you have it. Drop the plan within twelve months and you generally have a guaranteed right to buy a Medigap policy, with no health questions.

Guaranteed issue means no company can turn you down or charge you more for your health. Outside the trial right, Texas insurers can underwrite you, which means they read your health history and can say no. Confirm you can get a supplement before you drop the Advantage plan, not after. See switching back to Original Medicare.

If you are weighing whether to stay on Advantage or move back, talk it through with a licensed agent. Enter your ZIP code and we call you back, usually the same business day.

Good reasons to use it

Your doctor left the network, the plan's list of doctors and hospitals, on January 1 and you missed it in the fall.
A medication moved to a tier you cannot pay. A tier is a price level on the plan's drug list, its formulary.
The plan is denying or delaying care in a way you did not expect.
The plan's service area, the counties where it covers you, does not fit how you live.

How to avoid needing it

This window is here to fix choices made the fall before. Your plan mails an Annual Notice of Change (ANOC) each fall, a letter listing what changes in January.

Read it in October, check that your doctors are still in the network, and price your medications. See reading your ANOC and all the enrollment windows.

If you want to look at your options before March 31, we can go through them with you. Call our McAllen office at (956) 687 3334, or use the ZIP form on this page.

Common follow-up questions

Can I join an Advantage plan during this window if I am on Original Medicare?

No. It only works for people already in an Advantage plan. Joining one from Original Medicare takes Annual Enrollment, or a special enrollment period, a window opened by a life event such as a move.

How many changes can I make?

One. After it takes effect, you generally wait until October 15 for another chance.

Can I add a drug plan during this window?

Only if you are dropping your Advantage plan and going back to Original Medicare at the same time.

Want this looked at properly?

We are an independent agency in McAllen serving Hidalgo, Cameron and Starr counties. There is no obligation to talk it through.

Call (956) 687 3334

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