I was wondering if a provider who is in network with an insurance plan can refuse to bill and make a patient pay cash for certain services. This particular doctor provides Suboxone treatment (basically an office visit in order to write an RX for the meds each month for the patient) and its usually covered with most insurance plans just like any other office visit is since E/M codes are billed but the doctor is now refusing to take insurance and is making all those patients pay a cash rate out of pocket. $100 for follow up and $200 for new evals. Typically 99213, 99214 is commonly billed for these visits. Can the doctor do this?