Someone asked me: How much would single-payer healthcare cost in the USA?
It could be very cheap, but political realty makes me think it would cost about what is spend now.
There is a lot of evidence that we are overtreated (Overtreated: Why Too Much Medicine Is Making Us Sicker and Poorer: Shannon Brownlee: 9781582345796: Amazon.com: Books The Last Well Person: How to Stay Well Despite the Health-Care System: Nortin M. Hadler: 9780773532540: Amazon.com: Books Cut Medicine in Half Hanson on Health | EconTalk | Library of Economics and Liberty) but since the people over 65 are already covered and are politically active I think they will prevent us from doing what the NHS in the UL does and what they do the Netherlands.
To illustrate the point that absent politics you could implement single payer for cheap” Since probably 90% of the benefit of heath care comes from vaccination you could just cover them and say you have single payer. Further much of the rest of the benefit comes from trauma care, infant care and drugs (about 20% of health care by cost.)
Another thing that could be done to limit costs would be to squeeze providers like they do in Japan and Canada but with healthcare being up to 18 of the US economy the providers here are pretty powerful politically.
Another problem in the US is that states do most medical regulation so the Fed. Gov. paying for more creates a bad incentive: Before the Federal Government Starts to Pay for Even More Healthcare (expanded)
Here is an interesting article about the rise in medical costs: https://slatestarcodex.com/2017/02/09/considerations-on-cost-disease/
One additional thing to keep in mind is that health insurance premiums are motivation to work more in the taxed economy (rather than for in family consumption) but taxes are an incentive to not work in the taxed economy, mostly wives of good earners way the 2 alternatives and act on them.
BTW most countries do not have single payer but something like the PPACA but with a public option, Canada does though.
Very tough to tax another 9% of GDP (the Gov. already spends about half of medical care spending).