Here's the short answer. The Annual Notice of Change, or ANOC, is a letter from your Medicare Advantage or Medicare drug plan. It tells you about upcoming changes in your plan's coverage, costs, and more. Those changes take effect in January, and your plan must send you a printed copy by September 30. You do not have to do anything to keep your plan. If nothing important changed, you can stay put. If your costs went up, a drug you take was dropped, or your doctor left the network, you have from October 15 to December 7 to switch to a different plan. Any change you make starts January 1.
What the Annual Notice of Change is, and when it arrives
Plans can change their premiums, drug lists, and provider networks every year. Insurance companies can even decide each year whether to keep offering a plan in your area. The ANOC is the plan's required warning. It covers changes in coverage, costs, provider networks, and service area that start in January.
A second document, the Evidence of Coverage (EOC), comes a little later. It gives the full details of what the plan covers and what you pay next year. Plans send an EOC notice or printed copy by October 15. Think of it this way: the ANOC says what's different, and the EOC is the whole rulebook.
| Date | What happens |
|---|---|
| By September 30 | Your plan sends the Annual Notice of Change. |
| By October 15 | Your plan sends the Evidence of Coverage, or a notice on how to get it. |
| October 15 | Medicare Open Enrollment begins. You can join, drop, or switch plans. |
| December 7 | Open Enrollment ends. The plan must receive your request by this day. |
| January 1 | The changes in your ANOC take effect, and any new plan you picked starts. |
How to read the letter: six things to check
The letter compares this year with next year. Go straight to these items and circle anything that changed.
- Monthly premium. What you pay the plan each month, on top of your Part B premium. A small change here matters less than the items below.
- Deductible and copayments. Look at the medical deductible, the drug deductible, and the copay for the visits you actually use: primary care, specialists, hospital stays, and your regular prescriptions.
- Out-of-pocket maximum. The most you can pay for covered medical care in a year. If this number rose, a bad health year would cost you more. See how the out-of-pocket maximum works.
- Drug list (formulary). The ANOC flags drugs that are being dropped or moved to a higher cost tier. Check every drug you take. Plans can also add rules like prior authorization, step therapy, or quantity limits.
- Doctors, hospitals, and pharmacies. The ANOC covers changes to the provider network. The surest check is to call the offices you rely on and ask whether they'll be in the plan next year.
- Service area and extra benefits. A plan can shrink the counties it serves. Extras like dental, vision, hearing, or a benefits card can also change. Confirm them in the ANOC and EOC, not in an ad. See dental, vision, and hearing extras.
What to do next
If nothing important changed. Your drugs are still covered, your doctors are still in the network, and your costs look about the same. You can do nothing and stay in the plan. It renews on its own.
If something did change. Don't assume you're stuck. Use Open Enrollment, October 15 through December 7, to compare and switch. Here is Medicare's own checklist for choosing a plan:
- Compare plans in your area. Use Medicare Plan Finder at Medicare.gov/plan-compare. Enter the drugs you take to get an estimate of monthly and yearly costs for each plan. The back of the "Medicare & You" handbook also lists plans.
- Make sure the plan meets your needs. Check that it covers your prescriptions, ask your doctors and pharmacies if they're in the network, and review premiums, deductibles, and the yearly drug-cost estimate.
- Check other coverage first. If you have employer, union, or other coverage, talk to that benefits office before you change anything. If you live in another state part of the year, ask whether the plan covers you there.
- Join the new plan by December 7. Select "Enroll" in Plan Finder, contact the plan by phone or online, mail a paper form the plan must receive before the deadline, or call 1-800-MEDICARE (1-800-633-4227, TTY 1-877-486-2048). You don't need to cancel the old plan. It ends when the new one begins.
Free, unbiased help is one call away. Your State Health Insurance Assistance Program (SHIP) gives personal counseling and isn't connected to any insurance company or plan. Bring your ANOC to the appointment. Our Open Enrollment guide has this year's dates and a fuller checklist, and Choosing Coverage walks through the Original Medicare versus Medicare Advantage question without picking a side.
If the letter says your plan is ending
Some ANOCs deliver bigger news: the plan won't be offered next year. If a plan stops participating in Medicare, you have to join another Medicare health plan or return to Original Medicare. You can pick a new plan during Open Enrollment. You also get an extra window: when your plan's contract with Medicare isn't renewed, you can switch to another plan between December 8 and the last day of February. If you don't join another Medicare Advantage plan before your plan ends, you'll be enrolled in Original Medicare.
Landing in Original Medicare by default has two catches. You'd have no drug coverage unless you join a Part D plan, and Medigap has its own buying rules. Our guide to switching from Medicare Advantage to Original Medicare explains both.
Special situations
- You have Medicaid or Extra Help. You aren't limited to the fall window. You can change your drug coverage once each calendar month, and the change starts the first of the next month. See Dual-Eligible Coverage.
- Your drug is being dropped and you stay in the plan. When new coverage rules kick in, you may get a transition fill: a one-time, 30-day supply of a drug the plan no longer covers or now restricts. That buys time to ask for an exception. See Part D formulary exceptions and appeals.
- Your network changes a lot after December 7. Being told of a significant change in your plan's provider network can qualify you for a Special Enrollment Period, decided case by case, with 2 months to join or switch plans. Call 1-800-MEDICARE to ask.
- You missed December 7 and you're in Medicare Advantage. You get one more change between January 1 and March 31: switch to another Medicare Advantage plan, or return to Original Medicare and join a drug plan.
- A 5-star plan is available where you live. You can switch to it once between December 8 and November 30 of the following year.
Didn't get your ANOC?
If you don't get the ANOC and Evidence of Coverage in early fall, contact your plan. The member services number is on your plan ID card. Ask the plan to mail another copy, or sign up for an electronic version. Don't wait for it to turn up: the December 7 deadline doesn't move.
Watch out for look-alikes. Fall brings a wave of plan mailers, calls, and ads. The real ANOC comes from your current plan and names that plan on the letter. Never give your Medicare number to someone who calls you out of the blue. Our Medicare scams page lists the warning signs.
Common questions
Do I have to respond to the Annual Notice of Change?
No. It's information, not a form. If you do nothing, you stay in your plan with the new terms starting January 1. Respond only by switching plans if the changes don't work for you.
What's the difference between the ANOC and the Evidence of Coverage?
The ANOC lists what's changing in coverage, costs, and more for January. The Evidence of Coverage gives the full details of what the plan covers and how much you pay next year. The ANOC arrives by September 30 and the EOC by October 15.
My ANOC says my drug won't be covered next year. What are my options?
Compare plans during Open Enrollment and pick one that covers it. If you stay, you may get a one-time transition fill in January while you ask the plan for an exception. See Part D exceptions and appeals.
Can I switch to Original Medicare after reading my ANOC?
Yes, during Open Enrollment from October 15 to December 7, or during the Medicare Advantage Open Enrollment Period from January 1 to March 31. Buying a Medigap policy afterward is a separate question with its own rules. See Switching from Medicare Advantage to Original Medicare.
I'm on Original Medicare with a Part D plan. Do I get an ANOC?
Yes. Stand-alone Medicare drug plans send an ANOC and Evidence of Coverage every year, just like Medicare Advantage plans. Check the drug list and pharmacy changes the same way.
Official sources
- Medicare.gov: Mailings about costs (Plan Annual Notice of Change)
- Medicare.gov: "Medicare & You" handbook
- Medicare.gov: Joining a plan (enrollment periods and how to join)
- Medicare.gov: Special Enrollment Periods
- Medicare.gov: Drug plan rules (transition fills, prior authorization)
- Medicare Plan Finder