Every fall, your Medicare Advantage or Part D plan mails you an Annual Notice of Change, the document that tells you how your costs and coverage shift on January 1. It's the one piece of mail people set aside and then regret ignoring when a January copay or a dropped drug catches them off guard. This guide walks through what the Annual Notice of Change shows, how it differs from the Evidence of Coverage that arrives with it, and what to actually do once you've read it.
What the Annual Notice of Change is
If you're enrolled in a Medicare Advantage plan or a standalone Part D drug plan, your plan is required to tell you each year how it will change for the coming year. It does that through the Annual Notice of Change, usually shortened to ANOC.
The ANOC is a summary, not the full rulebook. It lays out the differences between your plan this year and your plan next year, side by side, so you can see at a glance what's moving. Those changes take effect on January 1. The kinds of things it covers include:
- Your monthly premium, deductible, and copays or coinsurance.
- The drug formulary, meaning which medications the plan covers and what tier each one sits on.
- The provider and pharmacy network, including whether your doctor or pharmacy is staying in the plan.
- Extra benefits, such as dental, vision, hearing, or over-the-counter allowances, that the plan may add, change, or drop.
Plans send the ANOC in the fall, generally by the end of September. That timing is deliberate: it lands before the Medicare Open Enrollment Period, also called the Annual Election Period, so you have time to read it and act if you need to.
How the ANOC differs from the Evidence of Coverage
The ANOC rarely shows up alone. It usually arrives alongside a second, much thicker document: the Evidence of Coverage, or EOC. People sometimes glance at the heft of the EOC, assume the whole packet is too dense to bother with, and put it all away. That's the mistake, because the two documents do very different jobs.
The Annual Notice of Change is the short summary of what's changing. The Evidence of Coverage is the long, detailed reference that explains exactly what the plan covers, how much you pay for each service, and the rules for getting care. Think of the ANOC as the "what's different this year" document and the EOC as the "everything about how this plan works" document.
For an annual review, the ANOC is where you start. It's built to be read quickly. You only need to reach for the EOC when the ANOC flags a change you want to understand in full, or when you have a specific question about how a benefit works.
What to check in the ANOC
When you open the ANOC, you're answering one question: does this plan still fit my life next year? Work through it with your own situation in front of you.
| What the ANOC shows | What to check |
|---|---|
| Next year's premium, deductible, and cost sharing | Whether the new monthly and out-of-pocket costs still fit your budget |
| The drug formulary for next year | Whether each medication you take is still covered, and on what tier |
| The provider and pharmacy network | Whether your doctors, specialists, and pharmacy are staying in network |
| Extra benefits being added, changed, or dropped | Whether a benefit you rely on, like dental or vision, is changing |
| Whether the plan is being discontinued | Whether you need to choose a new plan to keep coverage |
Pull out your list of prescriptions and your regular doctors, and read the ANOC against them, not in the abstract. A premium that rises a few dollars may not matter to you. A favorite medication moving to a higher tier, or your cardiologist leaving the network, very well might. The point of the review is to catch the changes that affect you specifically.
One change deserves special attention: if the ANOC says your plan won't be offered next year, that's not optional reading. A discontinued plan means you'll need to pick a new one during Open Enrollment, or you could be left without the coverage you're counting on.
What to do after you read it
Once you've gone through the ANOC, you'll land in one of two places.
If the plan still fits, you do nothing. As long as your plan is being offered again next year and you're satisfied with the changes, you stay enrolled automatically. There's no form to sign and no box to check. This is worth saying plainly, because people sometimes assume they have to re-enroll every year, and they don't.
If the plan no longer fits, you switch during the Medicare Open Enrollment Period, which runs October 15 to December 7. During that window you can move between Original Medicare and Medicare Advantage, change Part D drug plans, or pick a different Medicare Advantage plan. Whatever you choose takes effect January 1, the same day your current plan's changes would have. To compare your options, use the Medicare Plan Finder at medicare.gov/plan-compare, where you can enter your drugs and pharmacies and see how plans stack up on total cost. The plan's Star Ratings, which measure quality and member experience, also show up there and can help you weigh one plan against another.
If you miss the December 7 deadline, your options narrow. People already in a Medicare Advantage plan get a second, more limited window, the Medicare Advantage Open Enrollment Period, from January 1 to March 31, during which they can make one change. For the full set of windows and how they interact, see the enrollment periods guide.
The mistake to avoid
The single most common Medicare-coverage surprise is entirely preventable. Someone keeps the same plan year after year, never opens the ANOC, and then in January discovers their copay jumped, a medication dropped off the formulary, or their doctor is no longer in network. By then Open Enrollment has closed, and they're often stuck with the plan until the next window.
The fix takes maybe twenty minutes once a year. When the fall mail arrives, find the ANOC, read it against your own prescriptions and doctors, and decide whether to stay or switch before December 7. That habit is the difference between choosing your coverage and being surprised by it.
Frequently asked questions
Plans send the ANOC in the fall, generally by the end of September. That's deliberate, so it reaches you before the Medicare Open Enrollment Period that runs October 15 to December 7 and gives you time to compare plans if you want to switch.
No. If your plan is offered again next year and you're satisfied with the changes in the ANOC, you stay enrolled automatically. You only need to take action if you want to switch to a different plan or if your current plan is being discontinued.
The Annual Notice of Change is a short summary of what's changing in your plan for next year. The Evidence of Coverage is the longer, detailed document that explains exactly what the plan covers, what you pay, and the rules for getting care. Start with the ANOC; reach for the EOC when you need the full detail on a specific benefit.
If the ANOC says your plan won't be offered next year, you'll need to choose a new plan during Open Enrollment to keep coverage. You can compare your options on the Medicare Plan Finder at medicare.gov/plan-compare.
Learn More
- What Is Medicare? Parts A, B, C, and D explained
- Medicare enrollment periods and deadlines
- Medicare Star Ratings and what they mean
- Original Medicare vs. Medicare Advantage
Find personalized help reviewing your Medicare plan's annual changes at brevy.com.
The information on Brevy.com is for educational purposes only and is not a substitute for professional legal, financial, or medical advice. Rules vary by state and program and change frequently. Always verify with the relevant agency or a qualified professional. Brevy is not a law firm, financial advisor, or healthcare provider.