Enrollment & timing
KFF: Nine in Ten Medicare Advantage Enrollees Ages 65 and Older Have No Federal Guarantee They Can Buy Medigap if They Switch Back to Original Medicare
A KFF issue brief finds that medical underwriting rules block most Medicare Advantage enrollees from accessing Medigap supplemental coverage if they later want the broader provider access of original Medicare, a gap that grows more consequential as plan exits accelerate heading into 2027.
By the Goodsurance editorial teamAugust 3, 2026
Most people who enroll in Medicare have a protected window at the start, typically six months after turning 65 and enrolling in Part B, during which insurers must sell them a Medigap supplemental policy regardless of their health history. After that window closes, federal law in 46 states allows insurers to turn down applicants who have pre-existing conditions or charge them higher premiums based on health status.
A KFF issue brief published in February 2026 found that roughly 90 percent of Medicare Advantage enrollees ages 65 and older, representing approximately 22.4 million people, have no guaranteed right to buy Medigap outside that initial trial period under current federal rules. Only four states, Connecticut, Maine, Massachusetts, and New York, require insurers to sell Medigap policies on guaranteed-issue terms year-round or during at least one designated open period annually.
The finding carries added weight as Medicare Advantage plan exits accelerate ahead of the 2027 enrollment season. Beneficiaries who are involuntarily disenrolled from an MA plan and choose to return to original Medicare may discover that Medigap coverage, which pays most of the cost-sharing that original Medicare does not cover, is unavailable to them or priced out of reach due to health history.
KFF also noted that Medicare beneficiaries under age 65 who enrolled based on disability face even more limited Medigap protections in most states. Several states have enacted birthday rules or similar annual windows that offer partial relief, but the KFF researchers found the patchwork remains incomplete.
In plain words
When you first join Medicare at age 65, insurance companies must sell you a Medigap plan no matter what health problems you have. But this right only lasts for a short time. After that, if you join a Medicare Advantage plan and later want to switch back to regular Medicare, most states let insurers turn you down for Medigap because of past health problems. A health research group called KFF found that about 22.4 million Medicare Advantage members who are 65 or older face this risk. Only four states require insurers to sell Medigap to anyone who wants it. This matters more now because more Medicare Advantage plans are leaving markets, pushing people back toward regular Medicare when they may not be able to get Medigap coverage.
Understand the basics first
Source: KFF
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