I am not sure if I am correct on code selection on this one. The coding software I have shows the code we authed does not pair with the dx but the code I picked does. The doctor states he did an irrigation and debridement of the left hip post total hip arthroplasty (this is still in the global period). He re-incised previous incision saw that it went below the deep fascia and went completely down to the prosthesis. He irrigated with 9000 liters and scraped fibrinous tissue and exudate. Sent cultures. Which code is most appropriate--26991 or 27030? I am not sure because they are so similiar in there descriptions but since the doctor said he was doing and irrigation and debridement I feel I should bill that code even though it does not pair. Please help! Any advice would be appreciated. Thanks