Sen. Bernie Sanders described his Medicare for All legislation in a Fox News town hall the other night: “What we are talking about is simply a single-payer insurance program, which means that you will have a card which says Medicare on it, you go to any doctor that you want, you will go to any hospital that you want.” He added that “you’re not paying any more premiums, you’re not paying any more copayments, you’re not paying any more deductibles.” In another context, he said the plan “would allow all Americans, regardless of their income, to get the health care they need when they need it.”

Not...