Uh, that’s pretty much the definition of single-payer, at least as commonly used. From Wikipedia: Single-payer healthcare is a type of universal healthcare in

Uh, that’s pretty much the definition of single-payer, at least as commonly used. From Wikipedia: Single-payer healthcare is a type of universal healthcare in which the costs of essential healthcare for all residents are covered by a single public system (hence "single-payer"). The difference here being the US has a fractured system, with several government systems (but from the same government). Medicare for All would be try single payer.