The “Medicare for All” proposals espoused by various Democratic presidential candidates vary greatly in terms of benefits, provider payment arrangements, and the role of private insurance. In some versions, the government is the sole purchaser of medical services; in others, a publicly financed system would allow individuals to choose between a government plan and competing private insurers; in still others, a publicly managed option would be added to the wide variety of insurance and entitlement programs that already exist. There has also been a lively disagreement about whether individuals should be allowed to purchase private insurance to obtain better care than is available under a publicly financed plan.