Doctors are taught in American medical schools that they are supposed to provide all options to their patients and explain to them the cost benefits and not try

Doctors are taught in American medical schools that they are supposed to provide all options to their patients and explain to them the cost benefits and not try to make or even bias their decision. I'm not sure if it's simply for fear of lawsuits or if it's coded in the law itself (although I think I read that it's the latter somewhere).