Medicare Open Enrollment 2026: Dates, What You Can Change, and What to Watch For

Medicare Open Enrollment — officially called the Annual Enrollment Period (AEP) — is the window each fall when Medicare beneficiaries can make changes to their Medicare Advantage or Part D drug coverage. It runs from October 15 through December 7 every year. Any changes you make during this period take effect January 1 of the following year.

This is the primary opportunity most beneficiaries have to switch Medicare Advantage plans, drop Medicare Advantage and return to Original Medicare, add or change a Part D drug plan, or switch from one Part D plan to another.

During the Annual Enrollment Period you can: switch from one Medicare Advantage plan to another; drop Medicare Advantage and return to Original Medicare (Parts A and B); join a Medicare Advantage plan if you currently have Original Medicare; join, switch, or drop a Part D prescription drug plan; and switch from a Medicare Advantage plan that includes drug coverage to one that does not, or vice versa.

If you return to Original Medicare during AEP, you can also enroll in a standalone Part D drug plan at the same time.

Before the enrollment window opens, review your Annual Notice of Change (ANOC). Medicare Advantage and Part D plans are required to send this notice by September 30. It details any changes to your plan's premiums, deductibles, copayments, drug formulary, or network for the coming year.

Key things to check: whether your doctors and preferred hospitals are still in-network; whether your prescriptions are still covered and at what cost tier; whether your plan's out-of-pocket maximum has changed; and whether a competing plan offers meaningfully better coverage for your situation.

If you have Original Medicare with a Medigap plan, your Medigap coverage is not affected by AEP. However, this is a good time to review whether your Part D drug plan still covers your medications at a reasonable cost.

This year's open enrollment is particularly important for Humana Medicare Advantage members. Humana announced it is exiting a significant number of Medicare Advantage markets effective January 1, 2027. Members in affected plans will receive a notice and will need to select new coverage during the Annual Enrollment Period.

Humana members whose plans are being terminated may qualify for a Special Enrollment Period and may also have guaranteed-issue rights to enroll in a Medicare Supplement plan without medical underwriting, regardless of health status. If you received a plan termination notice from Humana, this is worth reviewing carefully before December 7.

In addition to the fall Annual Enrollment Period, there is a Medicare Advantage Open Enrollment Period from January 1 through March 31 each year. During this window, people already enrolled in a Medicare Advantage plan can switch to a different Medicare Advantage plan or return to Original Medicare (and join a Part D plan). This period does not allow you to join Medicare Advantage if you currently have Original Medicare.