National Health Service
A National Health Service would deliver services largely through publicly-owned clinics and hospitals employing salaried staff, and be governed by a federation of locally-elected boards. That will provide better accountability and cost control than a top-down Medicare-like national health insurance system paying mostly private providers to deliver health services.
Currently, Professor Gerald Friedman calculates that currently the national health bill is about $3.1 trillion, and that a Medicare for All would save about $600 billion in administrative costs and lower drug prices, so the national health bill in a single payer system would be about $2.5 trillion; but then he adds back about $350 billion to expand the system to handle services like long-term care and dental, so we have about $2.8 trillion for a single payer system
However, according to the OECD, health cost per person in the U.S. is $10,209 per person, while cost per person in the U.K. is only $4,264. With 330 million people, if we had a National Health Service with the same price per person as in the U.K, the cost would be about $1.4 trillion, or about $1.8 trillion adding in Friedman's expansion of services. Since we now spend about $700 billion on Medicare and $400 billion on Medicaid, then we could assume that the same $1.1 trillion would go to the NHS, while we would need $1.8 trillion, assuming the same cost per person as the UK NHS. This implies adding about $700 billion to the budget to get full coverage. This could be covered by the revenues covered in "How to pay for the Green New Deal". However, they could also be covered by keeping the current employer contributions to health insurance, which would go to the government instead of private insurers, about $400 billion, plus keeping the payments employees make for their health care (another $300 billion).
In other words, a Medicare for All system would cost $2.8 trillion, but assuming a similar cost as in the U.K., a $1.8 trillion system for a National Health Service. Could we really spend $1 trillion less with a National Health Service?
First, the Green New Deal will make Americans much healthier because they will 1) be provided with inexpensive organic food, including many more fruits and vegetables and 2) eventually there will be virtually no pollution. In addition, depending on how quickly walkable neighborhoods are constructed, the national health bill from car crashes will decrease, and the amount of walking will increase health. So let's say that would save $500 billion.
Second, let's add back $200 billion in case Americans can't be as efficient as Britons, and we have a national health bill of $2 trillion. If we assume that we keep the $700 billion from employer/employee contributions, then we only need to add $200 billion each year to get a full National Health Service for all Americans.