A federal rule most people never hear about until it affects them sets a hard floor on how much warning a Medicare Advantage member gets before their plan disappears. If an insurer decides not to renew its Medicare Advantage contract for the coming year, it cannot simply drop enrollees with a short heads-up. The notice has to reach each affected member by mail no later than 90 calendar days before the plan actually ends.
A 90-Day Floor Written Into Federal Regulation
The requirement comes from 42 CFR 422.506, the federal regulation governing how a Medicare Advantage organization exits a contract with the Centers for Medicare & Medicaid Services. Under paragraph (a)(2)(ii), an insurer that won’t renew must notify “each Medicare enrollee by mail at least 90 calendar days before the date on which the nonrenewal is effective.” That’s a minimum, not a target window Medicare hopes insurers hit. Most Medicare Advantage contracts run on the calendar year, so a plan ending December 31 has to have its nonrenewal letters in enrollees’ mailboxes no later than early October.
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What the Letter Is Required to Say
The full text of 42 CFR 422.506 doesn’t just set a deadline; it sets minimum content. The mailed notice has to tell the enrollee that the plan is ending and when, and it has to include information about the alternative coverage options available in that person’s region. The insurer must satisfy that second part in at least one of two ways: providing a CMS-approved written description of the other Medicare Advantage, Medicare Advantage prescription drug, and standalone Part D plans available where the enrollee lives, or placing outbound calls to affected members so they know who to contact about their options. In practice, most insurers do both, but the regulation only requires one.
Why the Math Lands in Early October
Ninety calendar days is longer than it sounds once you count backward from a December 31 contract end date. Ninety days before December 31 falls in early October, which puts the mailing window right at the start of the season when Medicare’s own machinery is gearing up. Medicare’s annual Open Enrollment period runs October 15 through December 7 every year, the window when anyone with Medicare can switch plans for coverage starting January 1. That’s not a coincidence the regulation spells out, but it is the practical effect: a nonrenewal letter mailed at the 90-day floor arrives in the same general timeframe as the season when a replacement plan can actually be chosen and takes effect cleanly.
A Separate Document From the Annual Notice of Change
It’s worth being precise about which letter this is, because Medicare Advantage members get more than one piece of official mail every fall. Every plan, whether it’s renewing or not, sends enrollees an Annual Notice of Change describing what’s different about their coverage, premium, or formulary for the coming year. That’s a routine update. The 90-day nonrenewal notice required by 422.506 is a different document entirely, sent only when a specific plan is exiting the Medicare market altogether and won’t exist for its enrollees the following year. Anyone who gets a letter announcing their plan is ending should not assume they’ve already seen it disguised as a routine annual update; the two serve different purposes and, when both apply, typically arrive separately.
What an Enrollee Can Do Once the Letter Arrives
A nonrenewal doesn’t leave a member without a next step. Medicare’s own guidance on Special Enrollment Periods confirms that when a Medicare Advantage, Medicare drug plan, or Medicare Cost Plan contract isn’t renewed, affected enrollees get a dedicated window to switch, running from December 8 through the last day of February the following year, separate from and in addition to the standard fall Open Enrollment Period. Anyone who doesn’t pick a new Medicare Advantage plan during that stretch is automatically returned to Original Medicare rather than left without any coverage. Combined with the regulation’s 90-day mailing floor, that means a member who gets a nonrenewal notice in early October has roughly five months, spanning both Open Enrollment and the dedicated Special Enrollment Period, to compare options before the old plan actually disappears.
The floor set by 42 CFR 422.506 doesn’t promise a member will love their next option or that a replacement plan will match the one that’s ending. What it guarantees is time: a minimum three-month runway between the insurer’s letter and the plan’s last day, timed to overlap with the exact stretch of the calendar when switching plans is easiest to do. A member who has heard nothing about their Medicare Advantage plan ending by mid-October, when a nonrenewal is scheduled for year-end, has a specific federal timing requirement to point to when they call their plan or 1-800-MEDICARE to ask what’s going on.
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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