In short
- Only people enrolled in a Medicare Advantage plan can use it, and only once per year.
- You can switch Medicare Advantage plans or go back to Original Medicare and join a standalone Part D plan.
- You cannot use it to move from Original Medicare into Medicare Advantage or to swap one standalone Part D plan for another.
- A change made in January starts February 1; in February, March 1; in March, April 1.
- Going back to Original Medicare does not guarantee you a Medigap policy. In Nebraska, outside your open enrollment or a guaranteed issue right, insurers can review your health.
The Medicare Advantage Open Enrollment Period (MA OEP) runs January 1 to March 31 every year. If you are in a Medicare Advantage plan, it gives you one change: move to a different Medicare Advantage plan, or leave Medicare Advantage for Original Medicare and pick up a standalone Part D drug plan.
It exists as a safety valve. Plans change every January 1, and sometimes you only find out a doctor or drug is a problem after the new plan year starts.
What can you do during Medicare Advantage Open Enrollment?
You can make one of two moves, according to Medicare's enrollment period fact sheet:
- Switch to another Medicare Advantage plan, with or without drug coverage.
- Drop your Medicare Advantage plan and return to Original Medicare. If you do, you can also join a standalone Medicare drug (Part D) plan.
The change takes effect the first day of the month after the new plan gets your request.
| Request received in | New coverage starts |
|---|---|
| January 2027 | February 1, 2027 |
| February 2027 | March 1, 2027 |
| March 2027 (by the 31st) | April 1, 2027 |
Joining a new Medicare Advantage plan automatically ends your old one, so you do not need to cancel it separately.
What can't you do during Medicare Advantage Open Enrollment?
This window is narrower than fall Annual Enrollment. You cannot:
- Switch from Original Medicare to Medicare Advantage
- Join a standalone Part D plan if you are already in Original Medicare
- Switch from one standalone Part D plan to another
- Make a second change after you use your one
Here is how it compares with the fall window:
| Annual Enrollment (Oct 15 to Dec 7) | Medicare Advantage Open Enrollment (Jan 1 to Mar 31) | |
|---|---|---|
| Who can use it | Everyone with Medicare | Only people in a Medicare Advantage plan |
| Original Medicare to Medicare Advantage | Yes | No |
| Medicare Advantage to another Medicare Advantage plan | Yes | Yes, once |
| Medicare Advantage to Original Medicare + Part D | Yes | Yes, once |
| Switch standalone Part D plans | Yes | No |
| Number of changes | You can change your mind during the window | One |
| When it starts | January 1 | First of the month after your request |
Who can use the Medicare Advantage Open Enrollment Period?
Anyone enrolled in a Medicare Advantage plan on January 1 can use it that year. That includes people who just switched plans during Annual Enrollment and do not like what they got.
There is also a version for new enrollees. If you are new to Medicare and join a Medicare Advantage plan, your window runs from the first month you have both Part A and Part B through the last day of your third month with both. For example, if your Medicare started May 1, 2027, you would have until July 31, 2027 to make your one change.
Why do people use this window?
The common reasons are problems that only show up after January 1:
- A doctor or hospital is not in the network. In Lincoln, Omaha and Grand Island, check your specific doctors and hospitals (for example at Bryan Health, CHI Health or Nebraska Medicine) with each plan. Networks are plan-specific and can change every year.
- A prescription costs more than expected. A drug moved to a higher tier, needs prior authorization, or is no longer on the formulary.
- A new diagnosis. A health change in December or January can make a different plan type a better fit.
- You picked in a hurry. Annual Enrollment is short, and the mail is overwhelming.
Example. A Lancaster County retiree joins a new Medicare Advantage plan during Annual Enrollment for 2027. In late January, she learns her cardiologist does not take the plan. On February 10, she enrolls in a different Medicare Advantage plan that does include him. Her new plan starts March 1, and her original plan covers her until then. She has now used her one change for 2027.
Plan availability, premiums, networks and benefits vary by county and change every year. Before you switch, confirm the new plan covers your doctors and your drug list. Our guide to switching plans walks through the steps.
What about Medigap if you go back to Original Medicare?
This is the catch. Leaving Medicare Advantage during this window returns you to Original Medicare, but it does not give you a right to buy a Medigap policy in most cases. Without one, you pay the Part A deductible ($1,736 per benefit period in 2026), the $283 Part B deductible and 20% of Part B costs with no yearly cap.
Federal law guarantees you a Medigap policy without health questions only in specific situations, including two trial rights:
- You joined Medicare Advantage when you were first eligible at 65 and are leaving within the first 12 months.
- You dropped a Medigap policy to join Medicare Advantage for the first time and are leaving within 12 months.
Outside those situations, the Nebraska Department of Insurance says companies "may refuse coverage because of health reasons." Nebraska does not have a birthday rule or an annual Medigap switching window. Read Medigap open enrollment and underwriting in Nebraska before you act.
How do you make the change?
To switch to a different Medicare Advantage plan, enroll in the new plan through the plan, Medicare.gov's Plan Finder, 1-800-MEDICARE or a licensed agent. Your old plan ends automatically.
To return to Original Medicare, join a standalone Part D plan, which ends your Medicare Advantage enrollment, or contact your plan or 1-800-MEDICARE to disenroll. If you skip Part D and lack other creditable drug coverage, a Part D late penalty may apply later.
For unbiased help, call 1-800-MEDICARE (1-800-633-4227), available 24 hours a day, 7 days a week (TTY 1-877-486-2048), or Nebraska SHIP at 1-800-234-7119. To weigh the bigger choice, read Medigap vs Medicare Advantage or see Medicare Advantage in Nebraska. If you want a second set of eyes on your options, talk to Bill.
Frequently asked questions
One. Between January 1 and March 31 you can make a single change: move to a different Medicare Advantage plan, with or without drug coverage, or leave Medicare Advantage and return to Original Medicare, where you can also join a standalone Part D plan. Once you use that change, you generally have to wait for Annual Enrollment or a Special Enrollment Period to change again.
Not with this window. The Medicare Advantage Open Enrollment Period is only for people already in a Medicare Advantage plan. If you have Original Medicare, your next regular chance to join Medicare Advantage is the Annual Enrollment Period, October 15 to December 7, unless you qualify for a Special Enrollment Period, such as joining a 5-star plan.
Only if you are leaving a Medicare Advantage plan. If you have Original Medicare with a standalone Part D plan, this window does not let you switch drug plans. People with Medicaid or Extra Help can change Part D plans once a month through a separate Special Enrollment Period, and anyone can join a 5-star Part D plan once during the year.
Maybe, but not automatically. If you are in your first 12 months of Medicare Advantage after joining at 65, or you dropped a Medigap policy to try Medicare Advantage for the first time, federal trial rights let you buy Medigap without health questions. Otherwise, Nebraska insurers can use medical underwriting and may decline you. Apply for the Medigap policy before you drop your plan.
On the first day of the month after the plan receives your request. A request received on January 20 starts coverage February 1; one received on March 31 starts April 1. You keep your old plan until the new coverage begins, so there is no gap, but keep using your old plan's network until the switch date.
Sources
- Medicare.gov: Understanding Medicare Advantage and drug plan enrollment periods (11219) (opens in a new tab)
- Medicare & You 2027 handbook (CMS Product 10050) (opens in a new tab)
- Medicare.gov: Choosing a Medigap Policy (02110) (opens in a new tab)
- Nebraska Department of Insurance: Medicare Supplement Fact Sheet 2026 (opens in a new tab)
- CMS: 2027 Medicare Advantage and Part D state fact sheets (opens in a new tab)
We do not offer every plan available in your area. Any information we provide is limited to those plans we do offer in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options. 1-800-MEDICARE (1-800-633-4227) is available 24 hours a day, 7 days a week. TTY users can call 1-877-486-2048.
