No worries :) The government pays for the NHS (National Health Service) and everything involved (hospitals, doctors etc.) from general taxation, so there aren't any insurance companies as we don't need to buy insurance; everyone is entitled to just walk into a hospital or make a doctors appointment and be treated (this doesn't include private healthcare or hospitals of course, you need insurance for them I believe, but the NHS is the majority of the healthcare provided in the UK).

I think St Mungo's is modelled after the NHS too, since JKR is British and there's no mention of paying anywhere in the books (plus, the Weasleys said they were in and out of there when Fred and George were kids, and I don't think they'd have been able to afford to do that if it wasn't free!).

Fairy//Hufflepuff
PS. Sam, you don't have to give points for this if you don't want to! ♥