The US spent $2 Trillion dollars on Medicare and Medicaid in 2024 [1][2]. If the US spent this money as efficiently as Japan (or UK [3], ...) it could pay for Healthcare for every single resident with this $2 Trillion dollars.
[1] https://www.kff.org/medicaid/medicaid-financing-the-basics/#...
[2] https://usafacts.org/answers/how-much-does-medicare-cost-the...