I had to go into surgery last year and had to sign a "I will pay whatever my insurance doesn't" form. I wrote in a clause saying that any out of network element

I had to go into surgery last year and had to sign a "I will pay whatever my insurance doesn't" form. I wrote in a clause saying that any out of network elements (persons, etc) must be personally approved in writing by myself or my proxy before they can do anything they bill for. I don't know if it would have held up in court, but it made me feel a little safer.