Insurers Have Already Told Wall Street Which Advantage Plans Die on December 31. Members Are the Last to Know, and the Letter Isn’t Due Until October 2.

Somewhere inside the Centers for Medicare & Medicaid Services (CMS) sits the list of Medicare Advantage plans that will stop existing on December 31, 2026. Insurers submitted their 2027 bids in June. Wall Street analysts have dissected the implications on earnings calls all summer. The people enrolled in those plans will find out by mail.

Members of continuing plans must receive an Annual Notice of Change by September 30. Someone whose plan is disappearing receives a separate nonrenewal notice by October 2. That leaves 90 days before the coverage ends, but only 66 days before Medicare Open Enrollment closes on December 7. Humana has confirmed that its 2027 plan exits will affect roughly 600,000 members. Other carriers are also shrinking their Medicare Advantage footprints. For anyone whose plan receives a nonrenewal notice, the letter opens a rare Medigap window that is remarkably easy to waste.

What the Carriers Already Told Their Shareholders

Humana (NYSE:HUM | HUM Price Prediction) said on its July 29, 2026 earnings call that 2027 plan exits will affect “approximately 600,000 members” and that “the majority of the plan exits were in plans with three and a half or lower ratings.” CFO Celeste Mellet described the strategy as cutting off “the lower tail of profitability.”

UnitedHealth Group (NYSE:UNH) told analysts on July 16, 2026 it expects “full-year Medicare Advantage enrollment to decline by approximately 1.1 million” and previewed “selective changes in market participation” for 2027. Press reporting has named 109 counties UnitedHealthcare is exiting.

Elevance Health (NYSE:ELV) already ran its playbook: Medicare Advantage membership fell 15.9% year over year in Q2. CFO Mark Kaye told investors the 2027 bids “placed an emphasis on plans where we can deliver sustainable value for seniors, particularly dual eligible members.” Plans that did not clear that bar were not refiled.

Centene (NYSE:CNC) is doing the same in miniature. CEO Sarah London said the plan is to “further simplify our Medicare Advantage footprint focusing our benefits increasingly on the duals population.”

The Door That Usually Stays Closed

When an Advantage plan does not renew, Medicare opens a Special Enrollment Period (SEP) from December 8, 2026, through February 28, 2027. The termination also gives members who return to Original Medicare a guaranteed-issue right to buy certain Medigap policies.

That protection begins 60 days before the existing coverage ends and continues for 63 days afterward. During the window, a Medigap insurer cannot deny coverage or charge more because of the applicant’s health history. For someone well past the initial six-month Medigap enrollment period, that is a door that may have been closed for years.

The catch is the destination, not which enrollment period the member uses. Someone who chooses another Advantage plan is not exercising the Medigap right because they are not returning to Original Medicare. They should not assume they can reconsider later and recover the same federal protection.

A $0 Premium Is Only Half the Math

The standard $202.90 Part B premium follows a member into either Original Medicare or Medicare Advantage. The added cost of returning to Original Medicare is a Medigap premium—perhaps $150 to $250 monthly, depending on the applicant and location—plus a standalone Part D plan.

In return, Plan G covers most Part A and Part B cost-sharing after the $283 Part B deductible. A $0-premium Advantage plan costs less upfront, but its in-network out-of-pocket maximum can reach $9,250 in 2026, alongside network restrictions and prior authorization.

The real question is which structure the member can afford during a bad medical year, especially if health later makes Medigap unavailable. Premium math is only half the picture either way: IRMAA surcharges and coverage gaps can quietly add thousands a year, which is why we mapped the full set of Medicare traps in a free guide here.

What to Do Sooner Than Later

The notice creates a short period in which both coverage systems are genuinely available, so three details deserve attention:

1. Open and save the nonrenewal notice. It documents the plan termination and the guaranteed-issue event.
2. Price Original Medicare, Medigap and Part D together before selecting another Advantage plan. Standardized Medigap coverage can carry sharply different premiums across insurers.
3. Compare any replacement Advantage plan’s doctors, drug formulary, authorization rules and out-of-pocket maximum. Ask the broker to price both paths before recommending either one.

The insurer decided which plan disappears. For a brief window, the member gets an unusually clean choice about what comes next and health history does not get a vote.

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