Proponents held up signs as Senator Bernie Sanders introduced the Medicare for All bill in Washington this month. : For a patient’s knee replacement, Medicare will pay a hospital $17,000. The same hospital can get more than twice as much, or about $37,000, for the same surgery on a patient with private insurance. Or take another example: One hospital would get about $4,200 from Medicare for removing someone’s gallbladder. The same hospital would get $7,400 from commercial insurers.