Medicare Enrollment Protection Act of 2025

Creates a one-time Medicare special enrollment period for people who have COBRA continuation coverage when they become eligible for Medicare, allows that SEP to be used only once in a lifetime, and sets Jan 1, 2026 as the start date for which COBRA coverage counts. It also changes rules about when Medicare coverage begins for these enrollees, bars COBRA plans from cutting benefits just because someone is Medicare-eligible but not enrolled in Part B, and requires updates to COBRA notices so beneficiaries understand how Medicare secondary payer rules apply. The change requires updates across the Social Security Act, ERISA, PHSA, and the Internal Revenue Code and directs the Department of Labor and HHS to revise participant notices.