Between now and the end of September, a document arrives that decides more household money than almost anything else in the Medicare year, and it looks like junk mail. It is the Annual Notice of Change, and it is the first place a member learns what their own plan will cost and cover in 2027 — weeks before the government publishes anything that would let them compare it with anything else.
The deadline is in the regulation, not in a press release
The requirement sits in federal rule rather than in a plan’s marketing calendar. Under the Medicare Advantage marketing regulations, the Annual Notice of Change is a standardized material that plans must provide annually, and it must be sent for enrollee receipt no later than September 30 of each year. The regulation adds a separate timing rule for members whose coverage takes effect on October 1, November 1 or December 1.
The word in the rule is receipt, and the delivery method has some flexibility: plans may deliver the notice electronically where a member has previously agreed to electronic delivery. For most members the notice comes on paper, in an envelope from the plan, in the second half of September.
A separate document, the Non-Renewal Notice, goes to members of plans that are leaving Medicare entirely. That is a different letter with a different date, and its arrival means the plan will not exist next year rather than that its terms are changing.
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Why it arrives before there is anything to compare it to
The sequencing is the reason this letter deserves more attention than it gets. In its July 28 fact sheet on 2027 Part D bid information, the Centers for Medicare & Medicaid Services states that as in past years, it will release the 2027 Medicare Advantage and Part D landscape in mid-to-late September, once all offerings are finalized, and that it will release final average premiums and other key information at the same time.
So for several weeks the notice in a member’s hands is the only concrete 2027 information they have. It describes one plan — their own — against a market nobody can see yet. That is a poor position from which to make a decision, and it is exactly the position most people are in when they read the letter and put it down.
The practical resolution is to treat the notice as a record rather than a decision point. Read it in September, mark what changed, and keep it. The comparison happens in October, when the landscape posts and the plan finder is loaded with 2027 data.
The four lines that matter in the letter
Most of an Annual Notice of Change is boilerplate, and the parts that move money are few. The premium is the obvious one, and the least important of the four, because it is usually the smallest number on the page.
The drug formulary is where the damage usually is. A drug moving to a higher tier, acquiring a prior authorization requirement, or dropping off the list entirely can change annual cost by more than any premium change will. Anyone taking a maintenance medication should check that specific drug by name against next year’s list rather than reading the summary.
The provider network is the second place to look, and for a Medicare Advantage member it can be the most consequential of all. A hospital or physician group leaving the network on January 1 changes where care can be received at in-network rates, and the notice is often the first written signal of it. The fourth is the out-of-pocket maximum and the plan’s cost-sharing structure — the copay for a specialist, the amount for an inpatient stay — which is what determines the cost of a bad year rather than an ordinary one.
What to do with it in September
The most useful thing a member can do with the notice takes about fifteen minutes and happens before the enrollment window opens. It is to write down four figures from the letter — next year’s premium, the drug tier for each prescription actually taken, whether the named hospital and physicians are still listed, and the out-of-pocket maximum — and keep that page with the notice.
Those four numbers are what a comparison in October is run against. Without them, the plan finder returns a list of alternatives with nothing to measure them by, and most people default to staying put because the work of reconstructing their own plan’s terms is more than they want to do in an eight-week window that also contains Thanksgiving.
It also helps to keep last year’s notice. A change that looks small in isolation — one drug tier, one copay — reads differently when it is the third consecutive year the same line has moved.
The window that follows
The decision period itself is fixed and short. Medicare’s Open Enrollment runs from October 15 through December 7, with any change taking effect January 1. Everything a member does with the September notice is preparation for those eight weeks.
Doing nothing is a decision with a specific consequence. A member who does not act is generally re-enrolled in the same plan under its 2027 terms — the new premium, the new formulary, the new network — as described in the notice they received in September. The letter is not a proposal awaiting agreement. It is a statement of what will happen automatically, and the only period in which that outcome can be changed opens on October 15 and closes on December 7.
This article was produced with AI assistance and reviewed by a human editor. Figures are linked to their primary sources; where a claim could not be verified from the public record, we say so.
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