Enrollment
Annual Election Period (AEP)
Quick answer
The Annual Election Period (AEP) runs October 15 – December 7 each year. During AEP anyone with Medicare can join, switch, or drop a Medicare Advantage or Part D plan. Changes take effect January 1.
Plain-English definition
AEP is the main once-a-year window to reshop your Medicare Advantage or Part D coverage after reviewing next year's Annual Notice of Change.
Why it matters
Plan benefits, formularies, and networks can change every year. AEP is when you make sure your plan still fits.
A simple example
You review your ANOC in September, compare next year's plans, and switch during AEP for a January 1 effective date.
Common mistakes & misconceptions
Related terms
Medicare Advantage Open Enrollment Period (OEP)
The Medicare Advantage Open Enrollment Period (OEP) runs January 1 – March 31. If you're already in a Medicare Advantage plan, you can switch to a different MA plan once or go back to Original Medicare (and add a PDP).
Special Enrollment Period (SEP)
A Special Enrollment Period (SEP) is a window outside the standard windows when you can join, switch, or drop a plan. SEPs are triggered by qualifying life events like moving, losing employer coverage, or becoming eligible for Medicaid.
Annual Notice of Change (ANOC)
The Annual Notice of Change (ANOC) is a document your plan mails you every September that summarizes what will change on January 1 — premiums, cost sharing, formulary, network, and benefits.
Frequently asked questions
Can I change more than once during AEP?+
Yes — your last submitted change wins.
Sources & references
📚 Where this information comes from
- Medicare.gov — official U.S. government site for people with Medicare ↗Primary source for benefits, enrollment periods, and plan comparison.
- CMS.gov — Centers for Medicare & Medicaid Services ↗Federal rulemaking, program updates, and official guidance.
- Social Security Administration — Medicare enrollment & premiums ↗Enrollment, premium withholding, and IRMAA determinations.
When you're ready, compare plans on your own terms
See Medicare Advantage plans from the insurance companies we represent, or walk the course with a licensed agent whenever you'd like a second set of eyes.
We help compare Medicare Advantage plans from the insurance companies we represent, and we don't offer every plan available in your area.
Medicare Caddies is an independent insurance agency. We are not affiliated with, endorsed by, or connected to the U.S. government, the federal Medicare program, or the Centers for Medicare & Medicaid Services (CMS). We help compare Medicare Advantage plans from the insurance companies we represent, and we don't offer every plan available in your area.