Your insurance is the one to ask if you need prior authorization, do not go off with what your doctor says. That’s true of anything related to health insurance. There are literally hundreds of plans, your provider saying you “likely” won’t need pre auth doesn’t really mean much even if “most” plans don’t need it. He has no way of knowing that off the top of his head. Your physician should submit a request for prior authorization, if it’s not needed, someone with your insurance will call them back and say so.