Another issue about billing for US hospital stays or ERs...more often than not, it's not just one bill - there's separate billing for: the bed/stay, each doctor you saw, each type of testing you had (Xrays, lab tests, etc), specialists or technicians who processed and/or read the tests, the medicines you were administered, any specialists who treated you (anesthetists, physical therapists, etc), any kind of special equipment you had to use, and so on and so forth. All in - it's mind boggling.
When I was a debt advice counsellor in the US, I used to have appointments with clients who would literally bring in grocery sacks full of medical bills that they could no longer face opening. There were always multiple bills for everything they had had done, and these had been passed on and on from one collection agency to another. The first appointment would be spent just opening all the post and sorting it into piles as to which bill was which, and who was collecting on it currently.
When I explain this to folks I know in the UK who have only ever known about and experienced the NHS, they suddenly have a greatly heightened appreciation of just what we have here.