Medicare Advantage Special Enrollment Periods: When You Can Change Plans Outside Open Enrollment

Many people think December 7 is their last chance to change a Medicare plan for a full year. That date is real, and it matters. But it is not the only door. When a big life event happens, Medicare can open a window of your own. That window is called a Special Enrollment Period. This guide lists the main events that open one, how long each window lasts, and what you can change in it. Our Medicare Advantage section holds more guides on plan rules and dates.

The fall window is not the only window

The Annual Enrollment Period runs from October 15 to December 7, 2026 (Ledger B4). In that window, most people with Medicare can change plans. Changes made then start on January 1.

A Special Enrollment Period is not the same thing. It is tied to an event in your life. The event starts the clock. The kind of change you can make, and the time you get, both depend on the event. If no event has happened, this door is not open.

Medicare keeps the full list of events on its Special Enrollment Periods page. This guide covers the events that come up most. If your case is not here, call Medicare and ask. Do not guess, since a wrong guess can leave you in the wrong plan for months.

You move to a new home

A move is the most common event. If you move to an address that is not in your plan service area, you can switch to a new Medicare Advantage plan or a drug plan. You can also go back to Original Medicare.

Your chance to switch starts when you move. It runs for 2 full months after you move. If you tell your plan before you move, your window starts the month before the move. It then runs for 2 full months after the move.

The same kind of window opens if you move to an address still in your plan area but with new plan choices. It also opens if you move back to the United States after living in another country. That window lasts for 2 full months after the month you move back.

One warning fits here. If you move out of your old plan area and do not join a new plan in this window, your old plan will drop you. Medicare will then put you in Original Medicare. That is safe as a backstop, but it may not be the cover you want. Pick a plan in the window if you can.

You lose other coverage

Losing coverage can also open a window. If you leave coverage from an employer or a union, that counts COBRA coverage too, you can join a Medicare Advantage plan or a drug plan. Your chance lasts for 2 full months after the month your coverage ends.

If you are no longer able to get Medicaid, you can join, switch, or drop plans. Your window lasts for 3 full months from the date you lose it or the date you are told, whichever is later.

If you lose other drug coverage that was as good as Medicare drug coverage, and you did not choose to lose it, you can join a plan with drug coverage. Your window lasts 2 full months after the month you lose it, or after you are told it is no longer as good, whichever is later.

Your plan changes its deal with Medicare

Some windows open because the plan changed, not because you did. Medicare can act against a plan that has problems. In that case, you can switch to a new plan. Your window starts when the act takes effect and lasts until it ends or until you switch.

If Medicare ends your plan contract, you can switch to a new plan. Your window starts 1 month before the contract ends. It ends 2 full months after the contract ends. If you do not join a new plan before your plan ends, you will be put in Original Medicare.

If your plan ends its contract, or its contract is not renewed, a window opens too. For a contract that is not renewed, you can switch from December 8 to the last day of February. Read any letter from your plan at once. The letter tells you the dates that fit your case.

Other events that open a window

Our guide on Medicare Advantage Open Enrollment from January to March shows the other window for people who are already in a plan on January 1. That window runs from January 1 to March 31, 2027 (Ledger B5). It lets you make one change, and it is not the same as the event windows in this guide.

Your plan letter each fall also matters. Our guide on the Annual Notice of Change shows how to read what will change on January 1.

• You live in a care home, like a nursing home. You can join, switch, or drop a plan while you live there and for 2 full months after you move out.
• You have both Medicare and Medicaid, or you get Extra Help with drug costs. You can change drug coverage once a month, and the change starts on the first day of the next month.
• You joined a Medicare Advantage plan when you were first able to at age 65. In the first 12 months, you can drop it and go back to Original Medicare.
• A plan with a 5-star rating is sold in your area. You can switch to that plan in a set window once a year.
• You dropped a Medigap policy the first time you joined a Medicare Advantage plan and you are still in your trial time. You can drop the plan and go back to Original Medicare.

How to use a window once it opens

Do not wait until the last week. If a form is lost or a date is read wrong, you need time to fix it. A window that closes does not reopen just because you were close.

• Write down the event and the date it happened.
• Ask Medicare how long your window lasts. The start date is not the same for each event.
• Check the new plan for your doctors, your hospital, and your drugs.
• Send your change before the window closes.
• Keep proof of the date you sent it and any letter that shows the event.

Who pays for what

• Original Medicare pays its share of covered care if you leave your plan and go back to it. It does not pay on top of a Medicare Advantage plan.
• Medicare Advantage plans are paid by Medicare to cover your care. Your plan pays for covered care under its own copays, network, and rules.
• Medicare Advantage members pay the Part B premium of $202.90 per month (Ledger A1), plus any plan premium and copays their plan sets.
• Part D drug plans pay their share of covered drugs under the plan drug list and cost steps. Your plan papers are the source for your own drug costs.
• Medicaid can help with costs for people who qualify through their state.
• Private pay covers care a plan does not cover and costs you owe with no other cover in place.

Sample situation

Ruth is 72 and has a Medicare Advantage plan. In March, she moves to a new town to be near her son. Her new home is not in her plan service area. She tells her plan about the move as soon as she knows her new address. Her window starts when she moves and runs for 2 full months after the move. In that time, she checks two plans sold in her new town. One plan lists her new doctor and covers her three daily drugs. She joins that plan and keeps the letter that shows her move date. She keeps paying her Part B premium of $202.90 per month (Ledger A1). Her old plan ends because she has left its area. She did not have to wait for the fall window, and she did not have a gap with no plan at all. She also wrote the end date of her window on her calendar the day she moved. That one step kept her from letting the time run out while she was still unpacking and finding new doctors in her new town.

What to check before you act

If you are not sure an event counts, ask before the window you think you have runs out. Call Medicare or a free counselor in your state. Tell them the event and its date. That is the fact they need to tell you if a window is open for you.

• Has a set event happened to you, or do you just want a new plan? Wanting a change is not an event.
• What date did the event happen, and have you kept proof of it?
• Does the new plan serve your new address, if you moved?
• Are your doctors and drugs covered by the new plan?
• How many days are left in your window?

Sources

• https://www.medicare.gov/basics/get-started-with-medicare/get-more-coverage/joining-a-plan/special-enrollment-periods