If you have Medicare Advantage or a Part D drug plan, an envelope marked "Annual Notice of Change" has probably landed in your mailbox. It's easy to set aside with the junk mail, but that packet may be the most important thing you read this fall. It tells you exactly how your plan is changing for 2027 — and whether it still fits your health needs and your budget.

What the Annual Notice of Change Actually Is

The Annual Notice of Change, or ANOC, is a document your Medicare Advantage or Part D plan is required to send you every year before the Medicare Annual Election Period (AEP) begins. It compares your plan's current benefits, costs, and rules to what will apply starting January 1 of the new year. Think of it as a "before and after" snapshot of your coverage.

The ANOC is different from the Evidence of Coverage (EOC), which is the full rulebook for your plan. The ANOC is the summary of what's changing; the EOC is the detailed reference you turn to when you need to know exactly how a rule works or whether a service needs approval first.

Because AEP runs each fall, the ANOC is timed to arrive with enough lead time for you to review it, compare it to other plans, and make a change if you want one. Skipping it means you could be auto-enrolled into a plan for another year without realizing your premium jumped, your favorite drug moved to a costlier tier, or a doctor you rely on is no longer in network.

The Big Three: Premiums, Drug Coverage, and Prior Authorization

Not every line in the ANOC matters equally. Focus your attention on three areas that tend to cause the most surprises.

Premiums and Cost-Sharing

Start with the monthly premium, but don't stop there. Look at:

  • Deductibles for medical and drug coverage
  • Copays or coinsurance for doctor visits, specialists, and hospital stays
  • The out-of-pocket maximum for the plan year

A plan with a slightly higher premium but lower copays for the services you actually use can end up cheaper overall. Do the math based on your real usage, not just the sticker price.

Drug Coverage Changes

Part D and Medicare Advantage plans update their drug formularies every year. Check whether your medications are:

  • Still covered at all
  • Moved to a different tier, which changes your copay
  • Now subject to step therapy or quantity limits
  • Requiring prior authorization for the first time

If a drug you depend on is being dropped or restricted, this is the single biggest reason to compare other plans during AEP rather than letting your current plan roll over automatically.

Prior Authorization and Network Changes

This is the section people skip most often — and the one that causes the most denials down the road. The ANOC will flag whether new services now require prior authorization, whether referral rules have changed, or whether your plan has adjusted its network of doctors, hospitals, or specialists.

Your plan's full list of services requiring prior authorization isn't always spelled out in detail in the ANOC itself. For the complete list, check your plan's Evidence of Coverage and its separately published prior authorization list — not the provider directory, which only tells you who's in network, not what needs approval first.

Red Flags Worth a Second Look

As you read through your ANOC, watch for these warning signs that your plan may no longer be the right fit:

  • A new prior authorization requirement on a treatment, test, or medication you use regularly.
  • Your specialist or hospital system dropping out of network, which could mean switching doctors mid-treatment.
  • A medication moving to a non-preferred tier, which can significantly raise what you pay at the pharmacy.
  • A lower out-of-pocket maximum being raised, which increases your financial risk if you have a bad health year.
  • Extra benefits disappearing, such as dental, vision, hearing, or a fitness allowance you've been using.

None of these changes are automatically deal-breakers, but each one is a reason to pause, compare, and decide whether to stay or switch during AEP.

What to Do With Your ANOC Before AEP Ends

Once you've read through the notice, take these steps:

  • Make a short list of the medications, doctors, and services that matter most to you.
  • Check each one against the 2027 changes in your ANOC.
  • Use Medicare.gov's Plan Finder tool to compare your current plan against others in your area.
  • Call 1-800-MEDICARE or your State Health Insurance Assistance Program if you want help walking through the comparison.

Because costs, formularies, and plan availability change every year, always confirm current premiums, deductibles, and enrollment dates directly at Medicare.gov or by calling 1-800-MEDICARE before you make a decision.

If a Prior Authorization Denial Happens Anyway

Even with careful planning, prior authorization rules can still lead to a denial once you're using the plan — especially if a service you assumed was covered now requires advance approval. If that happens, you have the right to appeal, and it's worth doing. A 2024 KFF analysis found that roughly 80% of appealed Medicare Advantage prior-authorization denials were overturned, even though only a small share of denied requests were appealed at all. In other words, appealing works far more often than most people expect, but it only works if you actually file.

If you're denied, look for the Integrated Denial Notice — formally called the Notice of Denial of Medical Coverage or Payment — which explains the reason for the denial and your appeal rights. For a standard Medicare Advantage appeal, you generally have 65 calendar days from the date on that notice to file your first-level appeal, known as a plan reconsideration. That clock runs from the notice date itself, not from whenever the letter happened to arrive, so it's worth marking your calendar right away. If your situation is urgent, you can request an expedited reconsideration, which the plan must decide within 72 hours.

If your plan upholds its denial after that first appeal, your case is automatically forwarded to the Independent Review Entity for a second look — you don't need to file anything separately to make that happen.

Keep in mind that Medicare Advantage members don't receive a Medicare Summary Notice; that document goes only to people with Original Medicare. Instead, your plan will send you an Explanation of Benefits and, if a claim is denied, the Integrated Denial Notice describing your appeal rights.

Don't Let the ANOC Gather Dust

Your Annual Notice of Change is one of the few times each year your plan is required to tell you, in plain terms, exactly what's about to change. Reading it carefully — and comparing it against your actual health needs — can save you from unpleasant surprises in January. And if a denial does slip through despite your best planning, remember that appealing is a normal, often successful part of using Medicare Advantage. Don't assume a denial is the final word before you've checked your rights and your deadlines.

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This article is general education, not legal or medical advice. Medicare rules, deadlines, and dollar amounts change; confirm the current details for your situation at Medicare.gov or by calling 1-800-MEDICARE. MedicareClaimDenied.com is not affiliated with or endorsed by Medicare, CMS, or any insurer.