Anesthesia Coding Alert

Question: Please explain the Medicare billing rules concerning the medical supervision of more than four concurrent cases, and the use of the -AD modifier.

Maryland Subscriber

Answer: Medical supervision is one anesthesiologist involved in more than four concurrent cases with CRNAs, AAs or residents. Modifier -AD notes to Medicare when cases go over four, and remains on all cases until all five are completed and no new cases are started. You must add -AD even if one or two cases are completed and only three remain (or any other amount). The modifier simply states that these cases were at some point involved in medical supervision.