What happens after the December 7 Medicare Open Enrollment deadline?

Updated November 10, 2026 · General information, not professional advice

Short answerMedicare's fall Open Enrollment ends Monday, December 7, 2026. The plan must receive your parent's enrollment request by that day, and the change starts January 1, 2027. If the deadline passes, your parent keeps their current coverage for 2027, but there are still a few ways to change: the Medicare Advantage Open Enrollment Period (January 1 to March 31, only for people already in Medicare Advantage), the 5-star Special Enrollment Period, and Special Enrollment Periods for events like a move.

The deadline, exactly

Open Enrollment runs October 15 to December 7. In 2026, December 7 falls on a Monday.
The plan must get the request by December 7. Enrolling online through Medicare.gov's Plan Finder or by calling 1-800-MEDICARE (1-800-633-4227) is the safest way to beat the date. Paper forms mailed late in the window may not arrive in time.
Every change made in the window starts January 1, 2027, no matter which day in October, November or December your parent enrolled.

What to finish before December 7

Read the plan's Annual Notice of Change. It lists 2027 changes to premiums, copays, drug coverage and networks.
Run your parent's drug list through the Plan Finder with their pharmacy. Drug plan costs often change more than anything else from year to year.
Check doctors and hospitals if your parent is in, or joining, a Medicare Advantage plan.
Make the change and save the confirmation number. When your parent joins a new Medicare Advantage or Part D plan, the old one ends automatically on December 31.

If the current plan still fits, your parent doesn't have to do anything: most plans renew automatically.

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If your parent misses December 7

Coverage doesn't stop. Your parent keeps the plan they have, under its 2027 terms. A few windows remain:

Medicare Advantage Open Enrollment, January 1 to March 31: people already in a Medicare Advantage plan can make one change, either switching Medicare Advantage plans or going back to Original Medicare and adding a Part D plan. The change starts the first of the month after the plan gets the request.
5-star Special Enrollment Period, December 8 to November 30: if a plan rated 5 stars is offered where your parent lives, they can switch into it once during that period.
Special Enrollment Periods for certain life events, such as moving out of the plan's service area, moving into or out of a nursing home, or losing other coverage. People with Medicaid or Extra Help have additional chances to change drug coverage.

People in Original Medicare with a standalone Part D plan generally can't switch drug plans after December 7 unless one of these exceptions applies.

What Open Enrollment doesn't cover

Medigap. Medigap policies aren't tied to Open Enrollment. In most states, outside your parent's one-time Medigap open enrollment or a guaranteed-issue situation, an insurer can use medical underwriting. Check before dropping Medicare Advantage if your parent would want Medigap.
Signing up for Medicare for the first time. That follows the Initial Enrollment Period around 65, or the General Enrollment Period, January 1 to March 31, for people who missed it.

Free, unbiased help is available from your State Health Insurance Assistance Program (SHIP). This guide is general information, not insurance advice.

Common questions

When is the Medicare Open Enrollment deadline for 2027 coverage?

Monday, December 7, 2026. The plan must receive the enrollment request by that day, and changes start January 1, 2027.

Can I change my Medicare plan after December 7?

Only in limited cases: the Medicare Advantage Open Enrollment Period from January 1 to March 31 if you're already in Medicare Advantage, the 5-star Special Enrollment Period, or a Special Enrollment Period for a qualifying event such as a move.

What happens if I do nothing during Open Enrollment?

Most plans renew automatically, so you keep your current plan under its new-year costs and rules. Read the Annual Notice of Change to know what's different.

Is December 7 the last day to change a Part D plan?

For most people in Original Medicare with a standalone drug plan, yes. Exceptions include the 5-star Special Enrollment Period and Special Enrollment Periods for events like moving or getting Extra Help.

Can I enroll by phone on December 7?

Yes. You can enroll through Medicare.gov's Plan Finder, by calling 1-800-MEDICARE (1-800-633-4227), or directly with the plan, as long as the plan gets your request by December 7.