As is well known, all healthcare in the United States is private, although the quality is excellent. To get certain medication which in Europe might be considered normal, a consultation is sometimes needed in the States.
Check your other policies
Before complicating things further, we recommend that you take a look at the insurance policies you already have, for example home or car, in case these services offer medical cover in other countries.
If, when buying your flight you pay by credit card, don't forget to check if your bank offers travel insurance. Many cards do indeed offer this service.
If you don't have any other policy that might cover you, the best thing to do is to contract private medical insurance. You should do so by clicking here before you travel.