I am off tracking this thread, probably. But I want to highlight how expensive the cost of treatments have now become in US. You will find lots of NY times and WSJ research articles on the topic. My recent one day ER visit and 2 nights stay ended costing me 5000 out of my pocket on top of what insurance had already covered, 19000. Well, that may not be exactly relevant to your case but all threaders in this post have unanimously agreed that health care costs are crazy here.
Since as a visitor, in your particular case, you might not be visiting ER. A general practicing or specialists medical centers might want you to pay upfront at the door. This is just so that you know.
Having said that, some of the Hospitals and Medical facilities are world class and may be really effective in your prognosis. One thing that many have also agreed and something that may be helpful in your decision. While ER care and immediate care, like surgeries, have delivered best in the class results amongst developed nations, US lags far behind when it comes to long term care, for example diabetes, chirrosis etc.