A nonrenewal letter arriving in October tells a Medicare Advantage member that coverage ends December 31, but it does not end the member’s chance to choose what happens next. Federal rules built specifically for this situation open a separate enrollment window the moment the letter goes out, one that runs well past the sign-up rush every other Medicare household faces each fall. That window begins December 8 and stays open through February 28, 2027, nearly three months longer than the standard enrollment period most beneficiaries rely on. The mechanics of that extra time, and a narrower right buried inside it, decide whether a canceled plan becomes a minor inconvenience or a permanently closed door.
A Second Clock the October Letter Starts
The extended window matters this year because insurers are shedding lower-rated Medicare Advantage contracts at scale. Humana told investors on its July 29, 2026 earnings call that roughly 600,000 members would be affected by 2027 plan exits, while UnitedHealth Group projected total Medicare Advantage enrollment would fall by about 1.1 million as it trims its 2027 footprint. Every affected member receives a nonrenewal notice by October 2, a full two months before December 8, the date the same notice makes necessary.
Medicare’s standard Open Enrollment Period runs October 15 through December 7 every year, the stretch most beneficiaries use to compare plans before January 1 coverage changes take effect. A member whose plan is not renewed gets something structurally different. Medicare’s own guidance on Special Enrollment Periods states that when a Medicare Advantage Plan, Medicare drug plan, or Medicare Cost Plan’s contract with Medicare isn’t renewed for the next contract year, the enrollee can switch to another plan between December 8 and the last day of February of the following year. For a contract ending December 31, 2026, that last day falls on February 28, 2027, since 2027 is not a leap year.
That calendar is longer, and later, than the Special Enrollment Periods Medicare grants when a plan’s contract ends abruptly mid-year rather than simply expiring at year’s end. CMS’s own guide to Medicare Advantage and Part D enrollment periods ties those mid-year windows to the exact termination date itself, opening only a matter of weeks before or after the contract ends rather than to a fixed calendar span. The year-end nonrenewal version instead starts after the fall Open Enrollment Period has already closed, giving a canceled member roughly twelve extra weeks beyond December 7 to settle on a replacement, precisely because the coverage gap itself does not begin until January 1.
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The Guaranteed-Issue Right Only One Path Keeps
That extended enrollment window covers two very different destinations, and only one of them carries a companion protection. A member who uses the window to enroll in another Medicare Advantage plan answers no medical questions and cannot be turned away, the same as anyone switching plans during standard Open Enrollment. A member who instead lets the nonrenewal return them to Original Medicare gains a separate, harder-to-earn right: the ability to buy a Medigap policy without medical underwriting, something otherwise limited to a person’s initial six-month enrollment period after turning 65.
That right exists because a Medigap insurer can otherwise deny an application, or price it using an applicant’s full medical history, once the standard enrollment period has passed. The Medicare Rights Center’s consumer guidance on Medigap guaranteed-issue rights explains that a person 65 or older qualifies for guaranteed issue within 63 days of losing certain kinds of coverage, including when a Medicare Advantage Plan ends its coverage. Reporting on this year’s nonrenewal wave has placed that protection as beginning roughly 60 days before the old coverage ends and closing 63 days afterward, layering a second countdown on top of the plan-switching deadline.
The distinction is not cosmetic. A member who spends the window shopping for a new zero-premium Advantage plan and later decides Original Medicare would have fit better cannot reclaim the guaranteed-issue right after the fact, because the right attaches to actually leaving Medicare Advantage for Original Medicare, not to a change of mind made afterward. Choosing between the two paths has to happen with the destination already decided, since the enrollment mechanics do not let a member test one option and default into the other’s protections later.
Where the Two Deadlines Diverge
Because the guaranteed-issue clock runs from the date coverage actually ends rather than from December 8, it does not close on the same day as the plan-switching window. Coverage ending December 31, 2026, plus a 63-day guaranteed-issue period reaches March 4, 2027, four days past the February 28 deadline to enroll in a replacement Medicare Advantage or Part D plan. A member who defaults into Original Medicare on January 1 because no new plan was chosen keeps a short buffer to shop for Medigap even after the plan-switching window has technically expired, though waiting that long forfeits any chance of landing in a different Advantage plan instead.
The stakes of missing either deadline are financial as much as medical. According to reporting on the 2027 nonrenewal wave, monthly Medigap premiums can run $150 to $250 depending on location and insurer, a cost layered on top of a standalone Part D plan and the Part B premium every Medicare beneficiary already pays. A member who misses the guaranteed-issue period entirely and later develops a health condition may find the same policies priced far higher, or refused outright, turning what looked like a paperwork deadline into a lasting gap in what coverage is even available to buy.
None of this changes what happens to a member who does nothing at all. Medicare’s guidance states plainly that anyone who does not join another Medicare Advantage plan before a nonrenewed contract ends is enrolled in Original Medicare automatically, with no Part D drug coverage and no Medigap policy attached unless the member separately applies for both. The February 28 deadline and the guaranteed-issue window trailing a few days behind it are not a grace period so much as a narrow, one-time opening; once both clocks expire, the same coverage decision reverts to ordinary underwriting rules that can price or deny a Medigap application based on health history for good.
This article was produced with AI assistance and reviewed by The Money Overview editorial team.
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