Medicare Advantage enrollment growth has slowed to approximately 2.5 percent in 2026, and several major insurers have withdrawn from over 100 counties. As network stability and plan availability shift, the ability to move between coverage types without losing financial protection becomes a more salient risk for beneficiaries and a structural factor for insurers. The same health conditions that drive a desire to leave Advantage — serious diagnoses, need for out-of-network specialists, repeated prior authorization denials — are the ones that trigger underwriting scrutiny on the Medigap side.
For investors, the episode underscores a linkage between Advantage plan design, Medigap market rules, and the predictability of retiree healthcare costs. The financial exposure of a household that cannot secure Medigap after leaving Advantage can shift from a known premium to variable cost-sharing that may reach the plan's out-of-pocket maximum. Whether state-level guaranteed-issue expansions or federal policy changes will alter that calculus remains an open question. Will the growing gap between Advantage enrollment and Medigap accessibility prompt regulatory action, or will the market continue to sort beneficiaries by health status at the point of switch?
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