Being on the other side of the healthcare "hate", the insurance company does not determine what is covered or not, it's whoever designed the plan that you are under, which in most cases is either your employer, association, or state. If the plan says ambulance rides aren't covered, or have a high deductible, then that's what you have to pay. That said, I can't tell you how many times a provider will input the wrong code into the system and the claim is improperly adjudicated. At work, we have 50 people on the phone all day long dealing with these kinds of things. So do your research. Verify your plan benefits with whoever provided the plan, not the insurer.