96413 is a valid covered Medicare procedure code and is for the administration of chemotherapy, intravenous infusion technique. So if that is what you are doing my next question would be are you getting this denial with any other carriers? If you are only getting this denial with UHC they may have a separate code that they require is used for reporting this service. Or the denial may be a mistake on their end. If UHC is the only carrier denying that code then I would start by contacting them and asking them to explain the denial.