Late September, a fat envelope shows up from your Medicare plan. Most people flip through it, do not understand it, and toss it in a drawer. That is a mistake. The ANOC is the single most important letter you get from your plan all year. It tells you exactly what is changing in January.
The short answer
The Annual Notice of Change (ANOC) is a required letter your Medicare Advantage or Part D plan sends by September 30. It lists every change coming in the new plan year. Read it, compare the changes to what you have now, and use the Annual Enrollment Period (October 15 to December 7) to switch if needed.
What the ANOC actually is
Every Medicare Advantage plan and every Part D drug plan has to file its 2027 rates and benefits with CMS in the spring. Once approved, plans must tell every current member exactly what is changing before the new year starts. That letter is the ANOC.
CMS requires the ANOC to reach you by September 30. Most plans mail it in the second or third week of the month. Some send an electronic version if you opted in.
If you have Original Medicare with no drug plan and no Advantage plan, you do not get an ANOC. There is nothing to change. Your Medigap plan sends its own renewal notice, which is different.
What is inside the ANOC
The ANOC is usually 20 to 40 pages. Most of it is boilerplate. The important parts are in the first 5 to 10 pages. Look for these:
- Monthly premium
- Annual deductible
- Maximum out-of-pocket (MOOP)
- Doctor and specialist copays
- Hospital copays
- Emergency room copay
- Prescription drug tiers and copays
- Preferred pharmacies
- Provider network changes
- Extra benefits: dental, vision, hearing, gym, transportation, over-the-counter allowance, flex card
- Star rating
The letter compares "what you had in 2026" against "what you will have in 2027." Any difference is highlighted.
Red flags to watch for
Not every change is bad. But some changes should make you pause and shop around.
Your drugs moved to a higher tier
Part D drugs sit on tiers 1 through 5, or sometimes 6. Tier 1 is cheapest, tier 5 is specialty. If a drug you take moved from tier 2 to tier 3, your copay jumped. If it moved from tier 3 to tier 4, it may have doubled or tripled.
This is the number one reason people should switch plans during AEP. A drug tier change alone can add hundreds or even thousands of dollars to your yearly cost.
A drug you take is no longer covered
Plans update their formularies every year. A drug that was covered in 2026 might not be covered in 2027. You will see it flagged in the ANOC. Options: switch plans, ask your doctor for an alternative, or file a formulary exception.
Your doctor left the network
Medicare Advantage plans change their provider networks every year. Doctors leave, new ones join. If your primary care doctor or a specialist you rely on is not in the new network, you will pay full out-of-network cost or switch doctors.
On HMO plans, you have to switch. On PPO plans, you can go out of network but at higher cost.
Your MOOP jumped significantly
The maximum out-of-pocket is the cap on what you spend for covered services in a year. Medicare Advantage MOOPs have been rising. If yours jumped by more than $500 or $1,000, that is a real cost increase in a bad year.
Extra benefits shrank
The flex card was $1,000 and now it is $500. The dental benefit was $2,500 and now it is $1,500. The gym membership is gone. These are common changes for 2027. Not the end of the world, but worth knowing.
Your plan is being discontinued
Rare, but it happens. If your plan is going away, you will get a bright orange letter separate from the ANOC. That letter also gives you a Special Enrollment Period so you have more time to pick a new plan.
ANOC vs EOC: what is the difference?
You will actually get two documents in the mail, often in the same envelope.
- ANOC (Annual Notice of Change): the summary of changes. Usually 20 to 40 pages. Read this one.
- EOC (Evidence of Coverage): the full plan document. Hundreds of pages. This is your reference book. Do not read cover to cover. Look up specific things as needed.
The ANOC is where the action is. The EOC is where you check the fine print later if a question comes up.
Your ANOC checklist
Sit down with the ANOC and a highlighter. Answer these seven questions:
- Is the monthly premium going up? If so, by how much per month? Multiply by 12 for the yearly bump.
- Is the deductible going up? Note the old and new numbers.
- Is the max out-of-pocket going up? This is your worst-case cost in a bad year.
- Are any of your prescriptions on a different tier? Look up each drug you take.
- Are your doctors still in network? Check the plan's provider directory, do not just assume.
- Are extra benefits changing? Dental, vision, hearing, gym, OTC card, transportation.
- What is the plan's new Star rating? A drop from 4 to 3 stars is a warning sign about service quality.
If two or more answers concern you, it is time to compare other plans.
Sample: what a 2027 ANOC change might look like
Here is what an ANOC line-by-line comparison looks like for a typical Medicare Advantage plan:
| Benefit | 2026 | 2027 |
|---|---|---|
| Monthly premium | $0 | $29 |
| Medical deductible | $0 | $250 |
| Primary care copay | $0 | $5 |
| Specialist copay | $40 | $45 |
| ER copay | $120 | $150 |
| Max out-of-pocket | $5,900 | $7,000 |
| Dental allowance | $2,500 | $1,500 |
| OTC / flex card (quarterly) | $100 | $50 |
The numbers above are just an example, not from any real plan. But this pattern (a plan tightening extra benefits and adding copays) has been common for 2027. The plan is not necessarily bad. It just may not be the best fit for you anymore.
Timeline: when things happen
Here is the full fall Medicare calendar:
- By September 30: ANOC and EOC arrive in your mailbox.
- October 1: Insurance companies can start marketing new 2027 plans.
- October 15: Annual Enrollment Period (AEP) begins.
- December 7: AEP ends. Last day to switch plans for 2027.
- January 1, 2027: Your new plan (or your same plan with 2027 changes) starts.
- January 1 to March 31: Medicare Advantage Open Enrollment Period. One more chance to change Advantage plans.
See our full AEP guide for a deeper walk-through of the enrollment window.
What to do if your ANOC never arrived
It happens. Mail gets lost, addresses get outdated, plans miss the deadline.
Steps to take:
- Check the plan's online portal or app. Most plans post the ANOC there too.
- Call member services. Ask for a copy to be mailed.
- Check with anyone at your address who may have grabbed the mail.
- If the plan cannot produce a copy by early October, file a complaint with 1-800-MEDICARE.
You still have your AEP rights even if the ANOC did not reach you. Do not miss December 7 because of a lost letter.
How to compare plans during AEP
Once you know your 2027 plan is not right for you, comparing is the next step. Three ways to do it:
Option 1: Medicare.gov Plan Finder
Free, official, thorough. Enter your ZIP code, drug list, and preferred pharmacies. It ranks plans by total yearly cost. The Medicare.gov Plan Finder is what most agents use too.
Option 2: Call 1-800-MEDICARE
Free, unbiased, but often long hold times during AEP. Best for straightforward questions.
Option 3: Talk to an independent agent
Free to you (agents get paid by the carrier, not by you). An independent agent works with multiple companies, so you get a real comparison. Ask them to run the Plan Finder together with you.
What if you also have Medigap?
If you have Original Medicare with a Medigap (Medicare Supplement) plan, the ANOC rules do not apply. Medigap plans do not send an ANOC because their benefits are standardized by federal law. Plan G in 2027 covers the same things Plan G covers in 2026.
What you may get from a Medigap carrier is a rate renewal notice. Premiums can go up each year. If your Medigap rate got expensive, you can shop for a lower rate with a different carrier (medical questions may apply). See how to compare Medigap companies.
What about your Part D plan?
Stand-alone Part D plans send their own ANOC. Same rules, same September 30 deadline. Most of the changes will be about drug tiers and premiums. The Part D $2,000 out-of-pocket cap from 2025 continues in 2027, which is one big protection for people on expensive drugs.
Common mistakes
Not opening the envelope at all
The plan can change big things and you never know. You wake up in January with a new premium, a new deductible, or a drug that costs three times more.
Assuming "no change" because nothing feels different
The changes take effect January 1. If you never opened the letter, the first sign is your first bill or first pharmacy trip in January.
Waiting until December to compare plans
By early December, agents are slammed and the Medicare.gov site gets slow. Start in mid-October when the tools are fresh and time is on your side.
Switching plans without checking the pharmacy
A new plan might have a better premium but not include your preferred pharmacy. Always run the Plan Finder with your pharmacy chosen.
Believing TV ads over your ANOC
The flex card commercials do not tell you the whole story. Your ANOC is the truth about your plan. Compare it against real plan documents, not ads. See what flex card ads actually mean.
Bottom line
Your ANOC is not junk mail. It is your yearly report card from the plan you already have. Every senior on Medicare Advantage or a Part D plan gets one by September 30. Open it, walk through the seven checklist items, and if anything looks off, use AEP to make a better choice.
Doing nothing means your plan stays the same, with all the 2027 changes baked in. That is fine if the changes are small and your health has not changed. It is not fine if your drugs got more expensive or your doctor left the network.
Not sure how your ANOC stacks up? Book a free call and we will look at it together. Bring the letter, your drug list, and your doctors. Twenty minutes usually does it.
Frequently asked questions
What is a Medicare Annual Notice of Change (ANOC)?
A required letter your Medicare Advantage or Part D plan sends every year by September 30. It shows every change coming to your plan next year.
When does the ANOC arrive?
By September 30 each year. Some plans mail earlier in September. Some send electronically.
What is the difference between ANOC and EOC?
ANOC is the summary of changes. EOC is the full plan document. Read the ANOC. Use the EOC as a reference book.
What should I look for in my ANOC?
Premium, deductible, MOOP, drug tiers, provider network, extra benefits. Also the Star rating. Any big change means it is time to compare plans.
What do I do if I do not like the changes?
Compare other plans during AEP (October 15 to December 7) and switch if a better option exists. Or drop Advantage for Original Medicare with Medigap.
What if I never got my ANOC?
Call your plan or check the online portal. If you cannot find it, file a complaint with 1-800-MEDICARE. You still have all your AEP rights.