Blog / Medicare Advantage

What is the Medicare Advantage Open Enrollment Period?

January 1 through March 31, and it only works in one direction. Here is exactly what it lets you do and what it does not.

Updated August 17, 2026 · 2 min read

Medicare Advantage Open Enrollment runs January 1 through March 31 every year. It exists as a correction window, for people who got into January and found the plan they chose was not what they expected.

Who can use it

Only people who are already enrolled in a Medicare Advantage plan on January 1. That is the whole eligibility requirement, and it is where the confusion starts.

What it lets you do

• Switch from your Advantage plan to a different Advantage plan
• Drop your Advantage plan and return to Original Medicare, and add a standalone Part D plan at the same time

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 more than one change. You get one, and it is done.

When your change takes effect

The first day of the month after the plan receives your request. Make a change in February and coverage starts March 1.

The Medigap problem

If you use this window to return to Original Medicare, you will want a supplement to cover the 20 percent. Whether you can buy one depends on whether you still have a protected window.

There is a trial right worth knowing about. If you joined an Advantage plan when you first became eligible for Medicare at 65, and you drop it within twelve months, you generally have a guaranteed right to buy a Medigap policy without health questions.

Outside that trial right, Texas insurers can underwrite you. Confirm you can actually get a supplement before you drop the Advantage plan, not after. See switching back to Original Medicare.

Good reasons to use it

• Your doctor left the network on January 1 and you did not catch it in the fall
• A medication moved to a tier you cannot afford under the new formulary
• The plan is denying or delaying care in a way you did not anticipate
• You realized the plan's service area does not work for how you actually live

The better plan is not needing it

This window exists to fix mistakes made in the fall. Reviewing your Annual Notice of Change in October, checking your doctors and pricing your medications is how you avoid needing a correction at all.

See reading your ANOC and all the enrollment windows.