At the interesting website Visual Capitalist, they ran a March 2017 article on how US public and private healthcare spending stacks up to other advanced countries.
Here's a version of the metrics I hadn't seen before. I'm simplifying - for details see the original blog. Roughly, per-citizen, advanced European countries spend about $4000 on publicly funded healthcare and $1000 on privately funding healthcare. The US spends $4500 on publicly funded health care PLUS $5000 on privately funded healthcare.
See the original charts and discussion here.
For one of the most interesting recent US proposals - Medicare Advantage Premium Support for All or MAPSA - see Billy Wynne's blog here.