Question: My provider was scheduled to perform a Vertiflex on a patient in the ASC. After he began administering monitored anesthesia care (MAC) and IV sedation, the patient became unresponsive and stopped breathing. The anesthesiologist assisted in ventilating the patient. After the patient awoke, the primary provider decided to cancel the procedure. Since anesthesia was provided and the procedure was cancelled, would I still bill for the procedure with modifier 53? Pennsylvania Subscriber Answer: No, you should not report modifier 53 (Discontinued procedure); bill for the anesthesia time. Modifier 53 will be submitted by the surgeon. You may, however, bill for your provider’s anesthesia time and include a code from the Z53 (Persons encountering health services for specific procedures and treatment, not carried out) ICD-10-CM diagnosis family to indicate that the procedure was aborted and explain why. List the Z53 code after the primary diagnosis.