Most people on Medicare do the same thing every fall: nothing. The Annual Enrollment Period opens on October 15, and they let it pass. Same plan, same coverage, no hassle. It feels like the smart, low-effort move—until January arrives and the costs don’t match what they expected.
Medicare plans are not permanent. Every year, insurance carriers may change what their plans cost, which drugs they cover, which providers are in-network, and what extra benefits they include. The plan you enrolled in last year isn’t necessarily the plan you still have today—it may have quietly changed on January 1. And if you didn’t review it during AEP, you probably didn’t realize it until something went wrong.
Medicare Plans Can Change Every Single Year
This is the part most people don’t know going in: your Medicare Advantage or Part D plan renews annually, but the terms of that renewal can look completely different from the year before.
Premiums can rise. Deductibles can change. Drugs you’ve been taking for years can move to a higher cost tier—or be dropped from the formulary entirely. Doctors and hospitals that were in-network can quietly move out. Dental and vision benefits that drew you to a plan can shrink or disappear. None of this requires any notice beyond the Annual Notice of Change that your plan mails you by September 30.
To understand just how much can shift between plan years, it’s worth looking at how your Medicare Advantage coverage may have changed—2026 brought a number of significant updates that caught many people off guard.
What the Annual Notice of Change Is (and Why It Matters)
Every fall, your insurance carrier is required to mail you a document called the Annual Notice of Change—the ANOC. It arrives before October 15, the start of the Annual Enrollment Period, and it’s supposed to give you everything you need to decide whether to stay on your current plan or switch.
Your ANOC will detail changes to your monthly premium, your annual deductible, your maximum out-of-pocket limit, your cost-sharing for doctor visits and hospital stays, your prescription drug coverage, and your provider network. It’s not a long letter from your insurer—it’s a detailed side-by-side of what your plan was and what it’s becoming on January 1.
The problem is that most people don’t read it. It lands in the mail and ends up in a pile. But what’s in that document is exactly why the October 15–December 7 enrollment window exists.
What Actually Happens When You Don’t Review
Let’s be specific about what “doing nothing” actually costs.
Higher prescription drug costs. Formularies change annually. A medication you’ve filled for years at a $10 copay might move to a tier that costs $60 or more—or be dropped from your plan’s coverage altogether. You’ll find out at the pharmacy, not in advance.
Out-of-network surprises. Medicare Advantage plans update their provider networks every year. Your primary care doctor, a specialist you’ve been seeing, or your preferred hospital can move out-of-network without much warning. If you haven’t verified that your providers are still covered, your next appointment could come with a much larger bill.
Lost benefits. Dental allowances, vision coverage, OTC benefit cards, and transportation perks are not guaranteed year to year. These are plan add-ons that carriers can reduce or remove entirely. The plan that covered two cleanings and an eye exam last year might only cover one—or none—this year.
Missed savings. New plans enter the market every fall. A plan in your area might cover your specific prescriptions at a lower tier, include your doctors, and cost less per month. You won’t know unless you look.
The Enrollment Window Is Short—and Closing Means Being Stuck
AEP runs from October 15 through December 7. If you want to switch plans, drop a plan, or change your Part D coverage, that window is it. Any changes you make take effect January 1.
Once December 7 passes, you’re generally locked into your plan for the rest of the year. The Medicare Advantage Open Enrollment Period (January 1–March 31) does allow one switch from one MA plan to another, or back to Original Medicare—but it doesn’t let you make wholesale changes the way AEP does.
There are Special Enrollment Periods for specific life events, including one triggered when your Medicare plan ends in your area due to a service area reduction. But a plan simply changing its costs or network doesn’t trigger an SEP. If your plan got worse but didn’t leave your county, you’d need to wait until next AEP to make a move.
How to Actually Review Your Plan Before AEP Ends
A good Medicare review doesn’t take all day. Here’s what matters.
Start with your ANOC. Read through the cost-sharing section and flag any changes that affect you—premium increases, new deductibles, updated out-of-pocket maximums. Then go through the formulary changes for any medications you take regularly.
Next, verify your providers. Go to your plan’s current provider directory and confirm your primary care doctor, specialists, and preferred hospital are still in-network. Don’t assume. Plans change these lists every year.
Then assess whether your current plan type still fits your life. If your health situation has changed—new prescriptions, more specialist visits, a new diagnosis—the plan you enrolled in when you were healthier might not be your best option anymore. Reviewing how to compare Medicare Advantage plans can help clarify what to look for when weighing your options.
And make sure you’re doing this before the deadline. If you’re close to December 7, the last-minute AEP checklist walks through exactly what to confirm before the window closes.
After AEP: What Comes Next
Whether you made a change or stayed put, there are a few things to do once enrollment closes. Confirm that any new plan details—your member ID, your coverage effective date, your provider directory—have been updated. Make sure your prescriptions are covered the way you expect under the new plan year. And know what your options look like if something changes mid-year.
For a clear breakdown of what to do once the enrollment period wraps up, what happens after AEP closes covers the next steps in detail.
The Real Cost of Not Looking
The financial impact of skipping your annual Medicare review rarely comes as a single big surprise. It’s a series of smaller ones—a prescription that costs three times as much, a specialist visit billed at out-of-network rates, a dental benefit you counted on that was cut in half. For a deeper look at how those costs stack up, Prepare for Medicare put together a thorough breakdown of the hidden costs of ignoring your Medicare plan that’s worth reading before you decide to let AEP pass.
FAQs
Do I have to change my Medicare plan every year?
No—you’re not required to make a change. But reviewing your plan each year during AEP is strongly recommended, because costs, drug coverage, provider networks, and benefits can all change on January 1 without any action on your part.
What is the Medicare Annual Enrollment Period?
AEP runs October 15 through December 7 each year. During this window, you can switch Medicare Advantage plans, change your Part D drug plan, drop Medicare Advantage and return to Original Medicare, or add a Part D plan.
What happens if I miss the Annual Enrollment Period?
You’ll generally remain on your current plan for the rest of the year. The only way to make changes outside of AEP is if you qualify for a Special Enrollment Period due to a specific life event—like your plan leaving your area.
What is the Annual Notice of Change (ANOC)?
The ANOC is a document your Medicare Advantage or Part D plan sends you by September 30 each year. It details every change your plan is making for the upcoming year—premiums, deductibles, formulary updates, network changes, and benefit adjustments.
How long does a Medicare plan review take?
With help from a Medicare specialist, a thorough plan review typically takes about 30 minutes. On your own, plan for at least an hour to review your ANOC, check your formulary, and verify your provider network.
Brickhouse Can Do This Review With You
You don’t have to sit down with a stack of plan documents and figure this out on your own. That’s what Brickhouse is here for.
We help Medicare beneficiaries go through their current plan, check formularies for the specific medications they take, verify that their providers are still in-network, and compare alternatives if a change makes sense. If you’ve been on the same plan for more than a year and haven’t looked at it recently, it’s worth taking 30 minutes to make sure it’s still working for you.
Reach out to the Brickhouse team anytime you have questions about what your coverage actually looks like going into the new year.
