Automatic Medicare Advantage Enrollment Could Lock Retirees Out of Medigap

Switching from a Medicare Advantage plan to Original Medicare later in life may result in a denial of Medigap supplemental coverage or significantly higher premiums. This risk is central to a proposal from the Trump administration and the Project 2025 policy roadmap to automatically enroll individuals into Medicare Advantage plans upon becoming eligible for Medicare.

Automatic enrollment would eliminate the late-enrollment penalty, which adds 10% to premiums for every year a person delays enrollment for the rest of their life. However, the default would place retirees in private insurance networks that require prior authorizations and cap out-of-pocket spending, rather than Original Medicare, which is accepted by most doctors nationwide. While Original Medicare users typically add Medigap plans for supplemental coverage, those automatically enrolled in Medicare Advantage would have to opt out or switch plans annually to regain that access. If they switch to Original Medicare after the initial enrollment period, they may be barred from purchasing a Medigap plan.