Medicare Annual Enrollment Period
Medicare Open Enrollment: October 15 – December 7, 2026
The once-a-year window to change your Medicare Advantage or Part D drug plan. Here is what you can do, what you can’t, and a week-by-week checklist that walks you through it — in plain language, with no pressure and nothing to sell you.
See the week-by-week checklist Open the plan-comparison tool
A note on names: this is Medicare’s enrollment window — different from the HealthCare.gov Marketplace open enrollment (Nov 1–Jan 15). If you buy your own insurance and are not on Medicare, those dates are not yours. The full walkthrough lives in the AEP guide.
Key dates at a glance
Three dates to circle. Each one carries its source so you can verify it yourself.
-
Oct15
Enrollment opens
Annual Enrollment begins
You can start comparing and switching Medicare Advantage and Part D plans.
Confirmed — CMS, cms.gov
-
Dec7
Last day to enroll
Annual Enrollment ends
Changes made by December 7 take effect January 1, 2027.
Confirmed — CMS, cms.gov
Any plan change you make between October 15 and December 7 takes effect on January 1, 2027. The full fall calendar — including the Medicare Advantage Open Enrollment that follows in the new year — is on the key-dates page.
What you can — and can’t — change
Annual Enrollment is Medicare’s main change window. Here is what is on the table, and what is not.
What you can do
- Switch Medicare Advantage plans — one MA plan to another, or from Original Medicare to an MA plan.
- Switch Part D prescription drug plans — drop your current drug plan and join a different one.
- Return to Original Medicare — drop an MA plan and go back to Parts A and B.
- Enroll in Medicare Advantage for the first time, if you already have both Part A and Part B.
- Add or drop Part D coverage — though dropping it can mean a late-enrollment penalty if you rejoin later.
What you generally can’t do
- No guaranteed-issue Medigap outside your initial enrollment period. Medigap (Medicare Supplement) insurers can require medical underwriting outside your 6-month Medigap Open Enrollment (the month you turn 65 and are enrolled in Part B) or certain protected situations — meaning they can decline you or charge more based on your health. A Medicare Advantage switch during AEP is not a Medigap right.
- You can’t use AEP to change Medigap plans freely. If Medigap is your question, check the rules before you drop anything — the decision that protects your MA switch can strand your supplement options.
The long version, with the edge cases, is in the AEP guide.
Your week-by-week checklist
Five steps from October 15 to December 7. Take them in order — steady progress beats a December scramble. Your checks are saved in this browser only.
Oct 15 – Oct 21 · Review your notices
Read the “Annual Notice of Change” (ANOC) letter from your current plan — it lists next year’s premiums, copays and drug-formulary changes.
Oct 22 – Oct 28 · Compare plans in the tool
See how your current plan stacks up against the alternatives for 2027.
Oct 29 – Nov 4 · Check the COLA announcement
Social Security announces the 2027 cost-of-living adjustment on October 14, 2026. If your Part B premium is deducted from your benefit check, the two move together.
Nov 5 – Nov 24 · Decide and enroll
Pick the plan that fits and enroll. Don’t wait until the last minute.
Nov 25 – Dec 7 · Confirm
Verify the enrollment went through. December 7 is the hard deadline.
2026 Medicare costs — verified
Current-year figures from official federal sources, confirmed first-hand. 2027 amounts appear here as soon as they are announced.
2026
Part B monthly premium
$202.90
Federal Register via GPO govinfo, confirmed September 28, 2026
2026
Part B annual deductible
$283
Federal Register via GPO govinfo, confirmed September 28, 2026
2026
Part D out-of-pocket cap
$2,100
CMS CY2026 Part D Redesign Program Instructions
2027
Part B monthly premium
Not yet announced
Awaiting the fall announcement
2027
Part B annual deductible
Not yet announced
Awaiting the fall announcement
How these figures are sourced and re-verified: Part B premium and your COLA.
The 2027 Social Security COLA
Announced each October. It moves your net benefit — and, if your Part B premium is deducted from your check, how that deduction changes.
Awaiting official announcement
The SSA announces the 2027 COLA on October 14, 2026.
TSCL projection: approximately 3.5% — an estimate by The Senior Citizens League based on inflation trends, not an official figure.
SSA, ssa.gov/cola · projection: tscl.org
Ready to compare plans?
Use the plan-comparison tool to see how your current plan stacks up against alternatives for 2027.
Sample data. The tool runs on clearly-labeled sample plans until CMS publishes the 2027 plan landscape files (expected October 2026). The comparison process is real — the specific plan details are examples.
You can also call 1-800-MEDICARE (1-800-633-4227) for free, one-on-one help. TTY users call 1-877-486-2048.
Our sources — so you can verify everything
Every number on this page is cited. If a figure is not yet official, the page says so instead of guessing.
- Enrollment windowCMS Medicare & You · 42 CFR 422.62
- Part B & Part D figuresFederal Register via GPO govinfo · CMS Part D Redesign Instructions
- COLASocial Security Administration
- COLA projectionThe Senior Citizens League
Think something here is wrong? How BenefitDial works · methodology · all guides. Data basis last verified September 28, 2026.