CPT modifier used for return to the operating room for a related procedure during the postoperative period. The physician may need to indicate that another procedure was performed during the postoperative period of the initial procedure. When this subsequent procedure is related to the first and requires the use of the operating room, it may be reported by adding the modifier -78 to the related procedure. (For repeat procedures on the same day, see modifier -76 .) This modifier may affect reimbursement, depending on the payer.