A peer-reviewed study published in JAMA this year found that roughly 2.9 million Medicare Advantage enrollees were forced out of their plans in 2026, a disenrollment rate of 10 percent that dwarfs the roughly 1 percent recorded most years from 2018 through 2024. The increase built quickly, climbing through an unusual 6.9 percent rate in 2025 before nearly doubling again the following year. For many of those enrollees, the notice that arrived this year was their first experience with a Medicare Advantage plan being pulled out from under them. Federal rule requires the next wave of nonrenewal letters, covering coverage exiting for 2027, to reach every affected member by October 2.
Seven Quiet Years, Then a Break in the Trend Line
The pattern comes from a study by researchers at the Johns Hopkins Bloomberg School of Public Health and Georgetown University, who linked county-level Medicare Advantage enrollment records to the federal government’s annual plan-crosswalk and service-area files covering 2017 through 2026. Their analysis found the mean forced-disenrollment rate held at 1.0 percent from 2018 through 2024. That baseline broke in 2025, when insurers began scaling back Medicare Advantage offerings amid tighter federal payments, and broke again in 2026, when the rate reached 10.0 percent overall and 12.4 percent among enrollees outside special needs plans.
The disruption was not spread evenly across the country. In 12 states, more than one in five Medicare Advantage enrollees faced forced disenrollment in 2026, and in Vermont the figure reached 92.2 percent of the state’s Advantage population, according to the published findings. Rural beneficiaries were displaced at roughly double the rate of enrollees in urban counties, and members enrolled in PPO plans, smaller insurance carriers, and plans rated below four stars were all overrepresented among those losing coverage compared with enrollees who kept their existing plan.
The authors tied the surge to changes in Medicare Advantage payment and risk-adjustment formulas together with a jump in health care utilization among enrollees, pressures that made some contracts unprofitable for insurers to continue. Big national carriers were not exempt, but they were underrepresented among the 2.9 million people forced out: Humana accounted for only 2.2 percent of that group compared with 18.2 percent of enrollees who kept their coverage, while smaller regional carriers and Blue Cross Blue Shield plans made up a much larger share of the exits. Enrollees who lost a plan built around a Part B premium reduction were also overrepresented, since only about a fifth of them had that benefit compared with roughly a third of enrollees who were not displaced.
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The Federal Rule Setting the October 2 Deadline
The October 2 date is not arbitrary. Under federal regulation, a Medicare Advantage organization that will not renew its contract must first notify the Centers for Medicare & Medicaid Services in writing by the first Monday in June, then notify every enrollee by mail at least 90 calendar days before the nonrenewal takes effect. Because nearly every Medicare Advantage contract runs on a calendar year and ends December 31, that 90-day countdown lands on October 2 in nearly every case, which is why plans exiting for 2027 must have their letters in the mail by that date this year.
CMS holds every nonrenewal letter to that same October 2 mailing date nationwide, largely so the guaranteed-issue Medigap rights the notice triggers apply uniformly no matter where an enrollee lives or when their specific insurer decided to exit. The notice itself must state the exact date coverage ends, describe the Medicare Advantage, Medicare Advantage prescription drug, and stand-alone drug plan alternatives available in the enrollee’s area, and list the 1-800-MEDICARE line and other resources for comparing options before making a new choice.
The notice also opens a Special Enrollment Period and, separately, a guaranteed-issue right to buy certain Medigap policies without medical underwriting, according to an analysis from the Center for Medicare Advocacy. That protection matters because Medigap insurers can otherwise deny an application, charge a higher premium, or impose a waiting period based on a person’s health history; enrollees who lose Medicare Advantage through a nonrenewal, rather than by choosing to leave, avoid those obstacles as long as they apply within 63 days of their coverage ending.
What the 2026 Numbers Signal for This Year’s Letters
The pressures the study identified behind the 2025 and 2026 spikes, tighter Medicare Advantage payment rates and higher-than-expected use of care, are structural rather than one-time events, which means insurers deciding this year whether to keep offering a plan in 2027 face many of the same financial calculations. Researchers have not yet published a count of how many enrollees will receive an October 2 letter this year, but the two-year run-up from roughly 1 percent to 10 percent gives no indication that forced exits are reverting to their historical rarity.
For an enrollee who does receive one of this year’s letters, the timeline is tight. October 2 falls roughly nine weeks before Medicare’s annual enrollment period closes on December 7, leaving a compressed window to compare replacement Medicare Advantage plans, weigh a return to traditional Medicare, or decide whether to exercise the Medigap guaranteed-issue right before it expires 63 days after coverage ends.
The study’s authors were careful to note what their data cannot show: how enrollees who were forced to switch actually fared, whether they moved to a comparable plan, returned to traditional Medicare, or ended up with thinner coverage than before. That welfare question remains unanswered even as the mechanism that produces it, a contract exit followed by a legally mandated October letter, is now running at roughly ten times its historical rate.
This article was produced with AI assistance and reviewed by The Money Overview editorial team.
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