Question: A patient developed a postop infection during the global period of a surgery and returned to the operating room (OR). Can we bill the hospital evaluation and management (E/M) visit with a modifier 24? Connecticut Subscriber Answer: You can only append modifier 24 (Unrelated evaluation and management service by the same physician or other qualified health care professional during a postoperative period) to an E/M service when the physician renders an E/M during the patient's global surgery period that is not related to the patient's surgery. If the infection is related to the surgery, the Medicare Administrative Contractor (MAC) considers it part of the original procedure unless the physician has to perform the procedure again. However, if the need is there to return to the operating room, the physician could bill the service with modifier 78 (Unplanned return to the operating/procedure room by the same physician or other qualified health care professional following initial procedure for a related procedure during the postoperative period). When you report modifier 24, the E/M service must meet the following requirements: According to MAC Noridian, you should never use modifier 24 in the following situations: