One of the reasons why I don't go to the USA anymore. Past 50 the chances of something medical popping up are higher than they were in the past and I just can't afford worrying about this. The total list of why I don't go there anymore is much longer but this is definitely one item on the list. This sucks because I have more friends in the USA than I do anywhere else and I miss them.
That shouldn't stop you. Comprehensive travel insurance can be had for short and long trips for $50 - $150. Prices for US travel insurance are around the same as insurance for visiting other developed countries such as Japan or Switzerland. All the terms are clearly spelled out.
