A bill to amend title XVIII of the Social Security Act to provide for an option for any citizen or permanent resident of the United States age 50 to 64 to buy into Medicare.

On November 10, 2026, Senator Tammy Baldwin (D-WI) introduced S5700, a bill to amend Title XVIII of the Social Security Act to create a Medicare buy-in option for U.S. citizens and permanent residents aged 50 to 64. The bill was read twice and referred to the Committee on Finance, marking its first legislative step. It has 9 cosponsors, all Democrats, indicating limited bipartisan support. The bill does not authorize or appropriate any specific funding; it creates a new eligibility pathway for Medicare, with premiums expected to cover costs. The money trail is indirect: if enacted, CMS would administer the new option, and private insurers offering Medicare Advantage plans could see expanded enrollment. However, the bill faces steep odds in the 119th Congress, where Republicans hold a 53-47 Senate majority. The Finance Committee is unlikely to advance the bill without significant modification or bipartisan compromise. Structural winners, if the bill were to pass, would be Medicare Advantage-focused insurers like UnitedHealth and Humana ($HUM), which could tap a new pool of roughly 50 million potential enrollees. Commercial insurers and employer-sponsored plans could face erosion as some individuals switch to Medicare. Hospitals and providers might see a shift from commercial to Medicare reimbursement rates, potentially compressing margins. The timeline is uncertain: the bill is at the earliest stage, with no hearings scheduled. Given the political landscape, the bill is unlikely to become law in this Congress.