Question: When contrast materials are given, is it allowable for the physician not to be in the office, and to have an NP or a PA instead? I know that level-two supervision states that the physician has to be in the office, although not necessarily in the exam room. Is it the same situation for an NP and a PA? If not, where are the rules? New York Subscriber Answer: The use of NPs and PAs as physician surrogates varies by state and licensure requirements and also as to whether the mid-level provider is functioning independently. However, these types of providers are allowed to administer other forms of intravenous medications and to bill as a provider albeit at a "discounted" rate as compared to physicians.