Medicare AEP 2026: What Changes and What to Check in Arizona

Medicare’s Annual Enrollment Period (AEP) runs October 15 through December 7, 2026. Any changes you make take effect January 1, 2027. Here’s what AEP actually covers, what’s new for 2026, and why it’s worth a look even if you’re not planning to change anything.

What AEP Actually Covers

AEP is specifically the window for changing Medicare Advantage and Part D prescription drug coverage — joining, switching, or dropping either. It is not the enrollment window for Medicare Supplement (Medigap) plans. Medigap doesn’t have a single national enrollment period the way Advantage and Part D do; you can generally shop for a Medigap plan at any time, though outside your original Medigap Open Enrollment window or a guaranteed-issue situation, carriers can medically underwrite you.

Why AEP Season Still Matters If You Have Medigap

Even though Medigap itself isn’t on the AEP calendar, fall is still the right time to check a few things:

• Your Part D drug plan — if you pair Medigap with a standalone Part D plan, that plan’s formulary and pricing can change every year, and AEP is your window to switch it.
• Your Medigap premium — carriers commonly adjust Medigap rates at renewal. If yours went up significantly, it’s worth comparing what else is available, especially if your health has stayed steady since you first enrolled.
• Whether Medicare Advantage still makes sense for you — if you’re on an Advantage plan and considering a move to Original Medicare plus Medigap, AEP is when you’d drop the Advantage plan; just know that moving to Medigap afterward may involve medical underwriting unless you qualify for guaranteed issue.

What’s Different for 2026

A few concrete numbers worth knowing this year:

• The standard Medicare Part B premium is $202.90/month for 2026, up from $185/month in 2025.
• The Part D out-of-pocket cap increased from $2,000 (2025) to a higher indexed amount for 2026, and enrollees can still choose to spread that cost across the year in equal monthly payments instead of paying it early.
• Some insurers are exiting the Medicare Advantage market or reducing plan offerings for 2026 — if that affects your current plan, you’ll likely get a notice from your carrier this fall, and it’s worth acting on it rather than setting it aside.

A Few Common Mistakes During AEP

Comparing plans on premium alone, without confirming your doctors and pharmacy are still in-network. Waiting until the first week of December to make a decision, which leaves little room to fix a mistake before the deadline. Assuming a plan that worked well last year hasn’t changed — formularies and networks are re-evaluated annually, not locked in.

How I Can Help

I don’t sell Medicare Advantage, so when you call me during AEP season, you’re not getting a pitch for a plan I have an incentive to sell. I’ll look at your current Part D coverage, your Medigap premium, and whether anything about your situation has changed — then tell you plainly whether it’s worth making a move or not. If you’re already my client, this is exactly the kind of annual check-in worth doing before December 7.

I’ve laid out the full turning-65 process in this Medicare checklist, and if Mayo Clinic access matters to your plan choice, I’ve covered exactly which plans keep it in-network in this breakdown.

Frequently Asked Questions

What are the AEP dates for 2026?

Medicare’s Annual Enrollment Period runs October 15 through December 7, 2026. Changes made during this window take effect January 1, 2027.

Does AEP apply to Medicare Supplement (Medigap) plans?

No. AEP covers Medicare Advantage and Part D prescription drug plan changes. Medigap doesn’t have a fixed annual enrollment period — you can generally apply anytime, though medical underwriting may apply outside your original Medigap Open Enrollment window or a guaranteed-issue situation.

What is the Medicare Part B premium for 2026?

The standard Part B premium for 2026 is $202.90 per month, up from $185 per month in 2025. Higher-income enrollees pay more.

What happens if I miss the December 7 AEP deadline?

If you miss AEP and don’t qualify for a Special Enrollment Period, you’ll generally need to wait for the Medicare Advantage Open Enrollment Period (January 1 – March 31), which has more limited options — it only allows switching between Medicare Advantage plans or dropping Advantage for Original Medicare, not adding or changing a standalone Part D plan.