Newsroom · Colorado
What Is the Annual Notice of Change Letter From Medicare?
It's your plan telling you, in writing and by law, what it's about to do differently on January 1.
The bottom line
- The Annual Notice of Change (ANOC) is a required letter from your Medicare Advantage or Part D plan listing every change taking effect January 1 — costs, coverage, drug tiers, network and service area (Medicare.gov).
- It has to reach you by September 30. Federal rule: for changes effective January 1, the plan must notify enrollees at least 15 days before the Annual Enrollment Period opens on October 15 (42 CFR §422.111(d)(2)).
- Check the drug tiers before the premium. A flat premium and a moved prescription is the most common way a plan gets more expensive without looking like it did.
- Doing nothing is a decision. If the plan continues you're auto-enrolled under the new terms. If it doesn't, doing nothing can leave you with no drug coverage at all.
- This year's letters describe 2027 — the year the Part D out-of-pocket cap rises from $2,100 to $2,400 and the standard deductible ceiling from $615 to $700 (CMS, April 6, 2026).
Every September a lot of perfectly sensible people throw this letter away. It arrives in a fat envelope with a booklet, the return address is an insurance company, and it looks exactly like the marketing that's been filling the mailbox since August. So it goes in the recycling, and in January something costs three times what it cost in December.
I'd rather that didn't happen to you, so here's what the letter is, why it's legally required to reach you before you're allowed to act on it, and the six lines inside it that actually decide whether you need to do anything.
What the letter is
The Annual Notice of Change — everyone in the business says "ANOC," rhymes with a-knock — is a side-by-side comparison of your plan this year and your plan next year. Medicare.gov's own description is about as plain as government prose gets: your plan sends it each fall, it includes any changes in coverage, costs and more that will be effective in January, and you should review those changes to decide whether the plan will continue to meet your needs.
Two things follow from that sentence and neither one is obvious.
First, it's about your plan, not about Medicare. Medicare Advantage plans and Part D drug plans are private contracts that get rewritten every single year. The premium, the copays, the deductible, the pharmacy tiers, the doctors in the network, the counties in the service area — all of it is set one contract year at a time. The ANOC is the only document that tells you what your specific plan did with that opportunity.
Second, it only reports what moved. That makes it short and readable, which is the point, but it also means a genuinely bad change can occupy one unremarkable row on page three.
Why September 30 is not a suggestion
The deadline is written into federal regulation. Under 42 CFR §422.111(d)(2), a Medicare Advantage organization must, for changes that take effect on January 1, "notify all enrollees at least 15 days before the beginning of the Annual Coordinated Election Period." That period opens October 15. Fifteen days before October 15 is September 30, and stand-alone Part D plans work to the same fall calendar.
The logic behind the rule is worth noticing, because it tells you how the letter is meant to be used. Congress and CMS built in a two-week gap between finding out and being able to do something about it. You are supposed to receive the bad news, sit with it, price alternatives, and then act when the window opens — not discover a formulary change in February and have no move left to make. Most people invert that: the letter sits unopened until December 3, and then there are four days to make a decision that deserved six weeks.
Source: 42 CFR §422.111 — Disclosure requirements (Medicare Advantage) · Medicare.gov — Plan Annual Notice of Change (ANOC). The Annual Enrollment Period runs October 15 – December 7 (Medicare.gov).
The six lines that decide whether you need to act
The letter is longer than it needs to be. On the first pass, read these six rows and nothing else — in this order, which is deliberately not the order the letter puts them in:
| Line | Why it's there | When |
|---|---|---|
| 1. Your drugs, tier by tier | A plan can hold its premium flat and still move one prescription from a preferred tier to a specialty tier. That single row can outweigh every other change in the letter combined. | Check first |
| 2. The provider network | Networks are renegotiated contract by contract. The ANOC flags network changes, but it won't name your cardiologist — you have to look your own doctors up in next year's directory. | Check first |
| 3. The out-of-pocket maximum | Your worst-case year, in one number. It's the least advertised figure in Medicare Advantage and the one that matters when something goes seriously wrong. | Check first |
| 4. The deductible | Separate deductibles can apply to medical and to drugs. The standard Part D deductible ceiling rises from $615 to $700 for 2027, so a plan that charged you nothing up front may not next year. | Then |
| 5. The monthly premium | The number everyone checks first and the one that explains the least. A premium can fall while copays rise. Read it after the four lines above, not before. | Then |
| 6. The service area | Rare but decisive. If your county drops out of the plan's service area, the plan is leaving you rather than the other way around — and that opens a Special Enrollment Period. | Then |
The drug tier line deserves the top spot and rarely gets it. Premiums are the number people check because premiums are the number people understand — it's a single figure, it's on the front page, and it's either up or down. But a formulary is where the real money moves. Shifting one maintenance medication from a preferred generic tier to a non-preferred or specialty tier can change what you pay for it by a factor you'd never guess from a premium that held steady. The letter will report both changes in the same font.
The network line has a similar trap in it. The ANOC will tell you the network changed. It will not tell you that your orthopedist is the one who left, because the letter is written for every member of the plan at once. That lookup is yours to do, in next year's directory, by physician name.
What's changing for 2027 no matter which plan you're in
Some of what shows up in this fall's letters isn't your insurer's doing at all — it's the program moving underneath every plan. CMS finalized the 2027 Part D benefit parameters in its April 6, 2026 rate announcement, and published the 2027 national baselines on July 28, 2026:
| Figure | 2026 | 2027 | What it means |
|---|---|---|---|
| Part D annual out-of-pocket cap | $2,100 | $2,400 | Permanent, written into law, indexed to drug-cost growth each year. Finalized April 6, 2026. |
| Standard Part D deductible (ceiling) | $615 | $700 | A ceiling, not a bill — plans may charge less. Finalized in the same CMS announcement. |
| Part D base beneficiary premium | $38.99 | $41.33 | A formula input CMS announced July 28, 2026, not a premium you are charged. Your plan's own number is in your ANOC. |
Sources: CMS — Announcement of CY 2027 Medicare Advantage Capitation Rates and Part C and Part D Payment Policies (April 6, 2026) · CMS — Medicare Part D 2027 National Average Monthly Bid Amount (July 28, 2026).
The out-of-pocket cap is the one to keep in perspective. It is going up, not away — it's a permanent protection indexed to drug-cost growth, $2,100 this year and $2,400 next. If you've seen a post claiming the cap is being taken away, it's wrong, and we walked through why in our piece on what's actually true about 2027 Part D premiums.
What the program figures can't tell you is your own number. Plan-level premiums for 2027 aren't public until CMS releases the fall landscape in late September. Your ANOC is where yours appears first.
If you do nothing
This is the part people get wrong in both directions, so let me split it cleanly.
If your plan is continuing: nothing happens, in the literal sense. You stay enrolled. You don't re-enroll every year, you don't reapply, and no one is going to call to confirm. On January 1 you simply wake up in the same plan under whatever terms that letter described. That's fine when the terms are fine. It is also exactly how someone ends up paying a specialty tier price all year for a drug that was tier 2 in December.
If your plan is NOT continuing: different letter, different stakes. A plan that's leaving your county, or leaving Medicare Advantage entirely, sends a separate non-renewal notice, and inaction there has teeth. You can land back in Original Medicare on January 1 with no drug plan at all — and once you've gone 63 days without creditable drug coverage, a Part D late enrollment penalty starts accruing and follows you permanently. Losing coverage does trigger a Special Enrollment Period, but a Special Enrollment Period is a door, not an escalator. Somebody has to walk through it.
We've written about the live version of this on the Western Slope: our look at what a carrier's 2027 Medicare Advantage exit could mean in Mesa County covers the non-renewal rules and the guaranteed-issue rights that come with them.
Reading it from a Grand Junction address
Two local facts make the network and formulary lines more consequential here than the letter's generic wording suggests.
The hospital list is short. Mesa County has 4 Medicare-certified hospitals: Intermountain Health St. Mary's Regional Hospital, Community Hospital, Grand Junction VA Medical Center, Family Health West Hospital. In a metro area with a dozen systems, a network change means driving somewhere else. Here it can mean a real question about where you'd be admitted, and for anything highly specialized, whether the answer is now Denver or Salt Lake. That makes the one-line network notice in your ANOC worth chasing down rather than noting.
Chronic conditions are common enough that formulary changes are not abstract. CDC PLACES puts high blood pressure at 26.6% of Mesa County adults, diabetes at 8.1%, and coronary heart disease at 5.2%. Those are exactly the conditions managed with daily maintenance medications — the prescriptions most exposed when a plan reshuffles its tiers.
Source: CDC PLACES, 2023 — via the Medicare On Main Data Desk, model-based prevalence among adults, Mesa County, CO · hospital list from CMS Hospital General Information (data.cms.gov).
If you're on Original Medicare with a Medicare Supplement, none of this applies to your medical coverage — a supplement is guaranteed renewable and has no network to change. You will still get an ANOC from your stand-alone Part D plan, and the drug tier line still deserves ten minutes.
Your calendar between now and December 7
| Date | What happens |
|---|---|
| By September 30, 2026 Act | Your ANOC must be in the mail. Open it the day it arrives and put it somewhere you'll find it again. |
| Late September 2026 Note | CMS publishes the 2027 plan landscape county by county, so the plans you could switch TO become visible. |
| October 15 – December 7, 2026 Act | The Annual Enrollment Period. Switch Advantage plans, switch drug plans, or move between Advantage and Original Medicare. Effective January 1. |
| January 1, 2027 Note | Everything in that letter takes effect, whether or not it was read. |
| January 1 – March 31, 2027 Note | Medicare Advantage Open Enrollment — if you're in an Advantage plan, one change, effective the first of the following month. A safety net, not a plan. |
Enrollment period dates: Medicare.gov — Joining a Medicare health or drug plan. Compare 2027 plans against your own drug list on medicare.gov/plan-compare once the landscape posts.
What I'd do with the envelope
- Open it the day it comes. Late September. Fat envelope, insurance return address, the words "Annual Notice of Change" on the first page.
- Find the drug table and look up your own prescriptions by name and dose. Not the summary — the table.
- Write down three numbers: premium, deductible, out-of-pocket maximum, this year beside next year.
- Look up each of your doctors in next year's directory, individually, and confirm with the clinic's billing office. A hospital staying in network doesn't mean the specialists inside it did.
- If anything moved, price alternatives on medicare.gov/plan-compare after the fall landscape posts, using your actual medication list.
- Decide before Thanksgiving. December 7 is a wall, and the first week of December is the worst week of the year to reach anybody who can help.
- Keep the Evidence of Coverage. You won't read it now. You'll want it the day something gets denied — and if that happens, here's how the appeal actually works.
How we know all this: the Medicare On Main Data Desk frames every article with primary public data — here, 42 CFR §422.111(d)(2) for the requirement that Medicare Advantage organizations notify enrollees at least 15 days before the Annual Coordinated Election Period begins; Medicare.gov's own Plan Annual Notice of Change page for what the letter contains and the October 15 – December 7 enrollment window; the CMS CY 2027 rate announcement of April 6, 2026 for the $2,100→$2,400 out-of-pocket threshold and the $615→$700 standard deductible; the CMS notice of July 28, 2026 for the $38.99→$41.33 base beneficiary premium; the CMS 2026 Parts A & B fact sheet of November 14, 2025 for the $202.90 Part B premium and $283 deductible; CDC PLACES County Data 2023 for the Mesa County prevalence figures; and the CMS Hospital General Information dataset for the county hospital list. Where a figure isn't public yet — your own plan's 2027 premium — we say so rather than estimate. No carrier is named or recommended anywhere on this page. This is education, not advice; confirm your plan, costs, and eligibility with a licensed agent or Medicare.gov. We take no payment from any carrier to feature a plan.
Frequently asked questions
What is the Annual Notice of Change (ANOC) in Medicare?
It's the letter your Medicare Advantage or Part D drug plan sends every fall listing exactly what changes about your coverage on January 1 — premium, deductible, copays, drug tiers, provider network and service area. Medicare.gov describes it plainly: the ANOC includes any changes in coverage, costs and more that will be effective in January, and you should review those changes to decide whether the plan will still meet your needs next year. It is not junk mail and it is not a sales piece. It is your own plan telling you, in writing, what it is about to do differently — and it is the only document that describes YOUR plan rather than the market in general.
When will my plan send my Annual Notice of Change?
By September 30, and most people get it in the last two weeks of the month. That date isn't a custom — it's regulation. Under 42 CFR §422.111(d)(2), for changes that take effect on January 1 a Medicare Advantage organization must notify all enrollees at least 15 days before the Annual Coordinated Election Period begins. That period starts October 15, which puts the mailing deadline at September 30 and leaves you roughly two weeks to read it before you can act on it. Part D drug plans follow the same fall timeline. If yours arrives combined with a thick booklet called the Evidence of Coverage, the ANOC is the short document in front.
What should I do with my Annual Notice of Change letter?
Read six lines and ignore the rest on the first pass: the monthly premium, the annual deductible, the out-of-pocket maximum, the tier your specific prescriptions sit on, whether your doctors and hospital are still in network, and whether the service area still includes your county. Everything else in the letter is context. Then compare — the Annual Enrollment Period runs October 15 through December 7, and anything you change takes effect January 1. What doesn't work is skimming it for a headline number. A plan can hold its premium flat and move one of your drugs from tier 2 to tier 4, and the letter will report both facts with equal calm.
What happens if I do nothing after I get my ANOC?
If your plan is continuing into next year, nothing dramatic — you stay enrolled automatically on January 1 under the new terms described in that letter. You don't re-enroll each year. The risk is that the new terms are the ones you never read. The second scenario is the one that hurts: if your plan is NOT continuing, you'll get a separate non-renewal notice, and doing nothing there can drop you back to Original Medicare with no drug coverage at all — which starts a Part D late enrollment penalty clock after 63 days without creditable coverage. Losing a plan does open a Special Enrollment Period, but you have to use it.
Do I get an Annual Notice of Change if I have Original Medicare?
Not one of these letters, no. The ANOC comes from a private plan — Medicare Advantage or a stand-alone Part D drug plan — because those contracts are rewritten every year. Original Medicare is set by federal law rather than by an insurer, so its 2027 premiums and deductibles arrive by CMS announcement instead, usually in November. If you have Original Medicare plus a stand-alone Part D plan, you will get an ANOC from the drug plan and nothing from Medicare itself. If you also carry a Medicare Supplement, that policy is guaranteed renewable — your carrier notifies you of rate changes separately, on its own schedule.
What's the difference between the ANOC and the Evidence of Coverage?
The ANOC is the diff; the Evidence of Coverage is the whole contract. The ANOC is a short side-by-side of this year versus next year, built to be skimmed in ten minutes, and it only shows what moved. The Evidence of Coverage is the full legal description of what the plan covers, what you pay, how appeals work, and what the rules are — a hundred pages or more, sent in the same envelope or posted online. Read the ANOC in September. Keep the Evidence of Coverage for the day you need to look up whether something specific is covered.
What if I never got my Annual Notice of Change letter?
Call the plan's member services number — it's on the back of your card — and ask them to resend it and to confirm the mailing address they have for you. Most missing ANOCs are address problems, and the same wrong address is about to miss your new member card and your Evidence of Coverage too. The letter is also normally posted in your online plan account by the end of September. Don't let a missing envelope become a missed enrollment period: the October 15 to December 7 window closes on schedule whether or not the mail found you.
Sources
- Medicare.gov — Plan Annual Notice of Change (ANOC) — what the ANOC is and what it contains.
- 42 CFR §422.111 — Disclosure requirements (Medicare Advantage) — the 15-day notice requirement that produces the September 30 deadline.
- CMS — Announcement of CY 2027 Medicare Advantage Capitation Rates and Part C and Part D Payment Policies (April 6, 2026) — 2027 Part D parameters: out-of-pocket threshold $2,100 → $2,400, deductible $615 → $700.
- CMS — Medicare Part D 2027 National Average Monthly Bid Amount (July 28, 2026) — the 2027 base beneficiary premium of $41.33.
- CMS — 2026 Medicare Parts A & B Premiums and Deductibles (Nov 14, 2025) — the $202.90 standard Part B premium and $283 deductible for 2026.
- Medicare.gov — Joining a Medicare health or drug plan — enrollment periods, including October 15 – December 7 and the January 1 – March 31 Advantage window.
- Medicare Plan Compare (Medicare.gov) — the official tool for pricing your own drugs against every plan in your ZIP.
- CMS — Medicare & You 2026 (official handbook) — Medicare's own plain-language handbook.
- CDC PLACES, 2023 — via the Medicare On Main Data Desk — Mesa County chronic-condition prevalence.
- CMS Hospital General Information (data.cms.gov) — the Medicare-certified hospitals in Mesa County.
