Annual Enrollment Period 2026: October 15 – December 7 Key Dates for Medicare Beneficiaries

The Medicare Annual Enrollment Period (AEP) — October 15 through December 7, 2026 — is the one time each year when most Medicare beneficiaries can change their Medicare Advantage or prescription drug coverage for the coming year. Whether you are happy with your current plan or shopping for something better, this window deserves your attention. Here are the key dates, what you can and cannot do, and how to prepare.

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What Is the Annual Enrollment Period?

AEP is the yearly window when you can join, switch, or drop a Medicare Advantage plan or a Part D prescription drug plan. Any changes you make take effect January 1 of the following year — so choices made during the 2026 AEP shape your coverage for 2027.

One important clarification: AEP generally does not apply to Medicare Supplement (Medigap) plans. You can apply for Medigap any time of year, subject to underwriting rules in most states. AEP is about Medicare Advantage and Part D.

What You Can Do During AEP

Switch from Original Medicare to a Medicare Advantage plan.
Switch from a Medicare Advantage plan back to Original Medicare.
Switch from one Medicare Advantage plan to another.
Join a Part D prescription drug plan, switch plans, or drop your drug coverage.

If you are happy with your current coverage and it is still being offered next year, you generally do not need to do anything — most plans renew automatically. But "automatic" is not the same as "optimal," which is why reviewing is still worthwhile.

Key Dates for the 2026 Annual Enrollment Period

Late September – early October 2026: Watch your mailbox for the Annual Notice of Change (ANOC) from your current plan, plus Evidence of Coverage documents. These spell out what is changing in your plan for next year — premiums, copays, drug tiers, and provider networks.
Early October 2026: Carriers announce plan exits and service-area changes for the coming year. If your plan is being discontinued, you will receive a separate notice (members in states like Oregon are seeing these around early October).
October 15, 2026: AEP begins. You can start enrolling in new coverage.
December 7, 2026: AEP ends. This is a hard deadline — in most cases, your choices are locked in after this date.
January 1, 2027: New coverage takes effect.
January 1 – March 31, 2027: Medicare Advantage Open Enrollment Period — a separate, more limited window for people already in a Medicare Advantage plan to switch plans or return to Original Medicare.

How to Review Your Coverage Before December 7

1. Read your Annual Notice of Change

This is the single most important document of the season. Plans change every year: a drug can move to a higher tier, a copay can rise, a doctor can leave the network. The ANOC tells you exactly what is different. Do not skip it.

2. Check your prescriptions

Make a list of every medication you take, then check each plan’s formulary (covered drug list) for next year. A plan that was cheapest last year can become expensive if one of your drugs moved tiers. This step alone saves many people real money.

3. Confirm your doctors and pharmacy

Provider networks shift. Verify that your doctors, specialists, and preferred pharmacy are still in-network for any plan you are considering — for 2027, not just for this year.

4. Compare total costs, not just premiums

A $0-premium plan with high copays can cost more over a year than a plan with a modest premium and lower cost-sharing — especially if you use care regularly. Look at the yearly out-of-pocket maximum too; it caps your worst-case spending.

5. If your plan is being discontinued, know your extra options

A discontinued plan generally gives you a Special Enrollment Period — and in many cases, Guaranteed Issue rights into a Medicare Supplement plan with no health questions. That can be a meaningful opportunity if you have wanted Medigap coverage but worried about underwriting. Ask a licensed producer whether it applies to your situation, and note the deadlines are strict (often 63 days).

A Note for People Considering a Medicare Supplement

AEP season prompts many people to reconsider the Medicare Advantage vs. Medicare Supplement question entirely. Remember: Medigap is not tied to AEP — you can explore it any time. But fall is a natural moment to compare, especially if your Advantage plan’s costs are rising or your plan is exiting. Residents of Maine have an extra advantage here: the state’s year-round switching rule lets you move to a same-or-lesser Medigap plan any month without underwriting. Rules in Oregon, Arizona, Florida, Texas, Indiana, Illinois, Kentucky, and other states vary — check what applies where you live.

The Bottom Line

October 15 to December 7 is your annual chance to make sure your Medicare coverage still fits your health, your doctors, your drugs, and your budget. Read the ANOC, check the formulary, confirm the network, and do not assume last year’s best plan is still this year’s. A little homework now prevents unwelcome surprises in January.

Want help reviewing your options before December 7? Call DT Senior Insurance at 1-877-752-1350 or fill out the lead form, and a licensed insurance producer will walk you through what’s available in your area.