Medicare Annual Enrollment 2026: what St. Louisans should review.

The short version: Medicare's Annual Enrollment Period runs October 15 through December 7, 2026. It is your once-a-year window to switch Medicare Advantage or Part D plans, with changes taking effect January 1, 2027. Even if you keep your plan, review it — premiums, copays, drug coverage, and networks can all change.

Thirty minutes of your time during AEP can save you a year of frustration.

Annual Enrollment runs October 15 through December 7 every year. It's the window when you can review your current Medicare plan, switch to a different one, and lock in the changes for the next plan year. If you don't actively make a change during AEP, your current plan rolls over into the next year — sometimes with different premiums, different copays, a different formulary, and different network.

That's the part folks miss. "Doing nothing" during AEP isn't actually doing nothing. It's accepting whatever changes the carrier made to your plan for the next year. Often the changes are minor. Sometimes they're material. The annual review is how you find out which.

The 60-second framing

AEP 2026 runs October 15 – December 7, 2026. During that window you can switch Medicare Advantage plans, switch from one Part D drug plan to another, switch from Original Medicare to Medicare Advantage, or switch from Medicare Advantage back to Original Medicare (and add a Part D plan). Whatever you elect during AEP takes effect January 1, 2027. Outside of AEP, your ability to change plans is limited to specific Special Enrollment Periods.

When is AEP 2026?

October 15 – December 7, 2026.

Anything you elect in that window is effective January 1, 2027. The new plan year starts then.

If you sit on a change until December 5 or 6, the carrier still has to process it before January 1 — and AEP is their busiest window. Earlier in the window is easier on everyone. We start scheduling annual reviews with our clients in mid-September.

What you can change during AEP

The AEP window allows several distinct changes:

• Switch from one Medicare Advantage plan to another.
• Switch from one Part D plan to another (if you're on Original Medicare).
• Switch from Original Medicare + a Part D plan to a Medicare Advantage plan (must include drug coverage or you have to elect a stand-alone Part D plan).
• Switch from a Medicare Advantage plan back to Original Medicare — and add a Part D plan if you need drug coverage. Note: picking up a Medicare Supplement when switching from Advantage back to Original Medicare may require medical underwriting in most states. See our Missouri Anniversary Rule article for the Missouri-specific path.

What you cannot do during AEP:

• Buy a new Medicare Supplement without underwriting (no AEP rule for Supplements; federal guaranteed-issue scenarios still apply).
• Drop Part A or Part B (those are separate processes through Social Security).
• Change your IRMAA bracket (that's the SSA-44 appeal process).

There's also the Medicare Advantage Open Enrollment Period (MA-OEP): January 1 – March 31, 2027. During MA-OEP, folks already on a Medicare Advantage plan can make one switch — to a different Advantage plan or back to Original Medicare + a Part D plan. It's a backstop window, but most plan changes are best handled during AEP.

What's new for plan year 2027

A few CMS rule changes that take effect October 1, 2026 affect how Medicare marketing and TPMO disclosures look this AEP.

Part D structural rules. The Part D out-of-pocket cap is $2,100 for 2026 (up from $2,000 in 2025) and continues into the 2027 plan year. The Medicare Prescription Payment Plan continues to be available.

For plan-specific changes (premium changes, benefit changes, formulary changes), the Annual Notice of Change (ANOC) from your carrier is the authoritative source. It arrives in late September each year. Read it before AEP starts. If you don't have yours, your carrier can resend.

5 questions to ask yourself before AEP

Before you decide whether your current plan still fits, work through these:

If three or more of these point to a review, AEP is the right time to do one.

How to compare plans in 30 minutes

The fastest reliable comparison uses Medicare.gov's Plan Finder:

A few minutes per plan, an hour total. If you want a second set of eyes, that's the consult we do this time of year.

Common AEP mistakes

We see these patterns every fall:

• "I'll just keep what I have." That's not a review. That's accepting whatever the carrier changed for the new year. Read the ANOC first.
• Picking the lowest-premium plan without running the drug list. Same mistake every year. A $0 or low-premium plan (Part B will still have a cost) that doesn't cover your medications well costs more than a higher-premium plan that does.
• Switching to a plan a friend has. Your friend has different doctors, different prescriptions, different pharmacy preferences, and may live in a different county with different available plans. Pick what fits you.
• Waiting until December 6 to decide. Earlier in AEP is easier. Carrier paperwork is less stressed. Mistakes can be corrected during the window. December is harder for everyone.
• Assuming an Advantage plan's dental or hearing benefit covers everything. Read the actual benefit limits. Many benefits have annual dollar caps that are meaningful but not unlimited.
• Switching out of a Medicare Supplement during AEP without understanding underwriting. If you're on Original Medicare + a Supplement and you switch to Medicare Advantage during AEP, picking the Supplement back up later may require medical underwriting. Don't switch lightly.

Talking to a St. Louis advisor

Our AEP process looks like this:

1. Annual review appointment (we start booking in mid-September).
2. Scope of Appointment signed before any plan-specific discussion (CMS rule).
3. Plan-fit conversation — your doctors, your drugs, your pharmacy, your travel, your extras usage, your situation changes.
4. Plan Finder run on plans available in your county.
5. Honest recommendation — sometimes the current plan is the right plan and we say so. Sometimes there's a clearly better fit and we walk you through the trade-offs.
6. Enrollment paperwork only after you decide and only if you decide to switch.

We do annual reviews for every active client. We also do them for non-clients during AEP for free. If the review confirms you're on the right plan, great. If it points to a better fit, we'll explain why.

I've been helping people with Medicare in St. Louis since 2013. The annual review is the most important touchpoint of the Medicare year for most folks, and the easiest one to skip.

No fee, no pressure, no sales pitch — that's the rule of the house. We answer every call.

Why not just do it yourself?

You can. Medicare's Plan Finder is free and open to everyone. But here's what a lot of people don't realize: using a licensed agent doesn't cost you anything extra. We're paid by the insurance company, not by you — your premium is identical whether you enroll through us or on your own, and it's against Medicare's rules for an agent to charge you a fee. So it's not “pay for help, or do it free.” It's “do it alone, or do it with someone who runs this every day — for the same price.”

When you switch or renew through us, we run your exact drugs and doctors against every plan in your county, catch the gotchas before they cost you, handle the paperwork, and we're still here in January when a claim or a card problem comes up. That's the part the Plan Finder can't do. Don't do it alone — let's do it together.