Physicians report the appropriate anesthesia modifier to denote whether the service was personally performed, medically directed, or medically supervised.
Specific anesthesia modifiers include:
AA - Anesthesia Services performed personally by the anesthesiologist;
AD - Medical Supervision by a physician; more than 4 concurrent anesthesia procedures;
G8 - Monitored anesthesia care (MAC) for deep complex complicated, or markedly invasive surgical procedures;
G9 - Monitored anesthesia care for patient who has a history of severe cardio-pulmonary condition;
QK - Medical direction of two, three or four concurrent anesthesia procedures involving qualified individuals;
QS - Monitored anesthesia care service;
QX - CRNA service; with medical direction by a physician;
QY - Medical direction of one certified registered nurse anesthetist by an anesthesiologist;
QZ - CRNA service: without medical direction by a physician; and
GC - these services have been performed by a resident under the direction of a teaching physician.
The GC modifier is reported by the teaching physician to indicate he/she rendered the service in compliance with the teaching physician requirements in §100.1.2. One of the payment modifiers must be used in conjunction with the GC modifier.
The QS modifier is for informational purposes. Providers must report actual anesthesia time on the claim.
The Part B Contractor must determine payment for anesthesia in accordance with these instructions. They must be able to determine the uniform base unit that is assigned to the anesthesia code and apply the appropriate reduction where the anesthesia procedure is medically directed. They must also be able to determine the number of anesthesia time units from actual anesthesia time reported on the claim. The Part B Contractor must multiply allowable units by the anesthesia-specific conversion factor used to determine fee schedule payment for the payment area.