Monitored Anesthesia Care (MAC)

Monitored Anesthesia Care (MAC) is a covered service when the anesthesia service and the procedure for which MAC is given are both a Medicare benefit and medically reasonable and necessary.

In keeping with the American Society of Anesthesiologists' standards for monitoring, MAC should be provided by qualified anesthesia personnel (anesthesiologists or qualified anesthetists such as certified registered nurse anesthetists [CRNA] or anesthesia assistants). These individuals must be continuously present to monitor the patient and provide anesthesia care.

The following quote is from Guidelines for the Use of Deep Sedation and Anesthesia for GI Endoscopy, "Gastrointestinal Endoscopy," Volume 56, No. 5, 2002, p. 616: "The routine assistance of an anesthesiologist for average risk patients undergoing standard upper and lower endoscopic procedures is not warranted and is cost prohibitive. MAC for these procedures must be justified by the presence of one of the listed qualifying conditions.”

During MAC, the patient's oxygenation, ventilation, circulation and temperature are monitored to anticipate the need for general anesthesia administration or for the treatment of adverse physiologic reactions. In addition, the possibility that the surgical procedure may become more extensive, and/or result in unforeseen complications, requires comprehensive monitoring and/or anesthetic intervention.

CMS requirements for MAC are the same as for general anesthesia with regard to the performance of pre-anesthetic examination, prescription of the anesthesia care, the completion of an anesthesia record, the administration of necessary oral or parenteral medications and the provision of indicated post-operative anesthesia care. Appropriate documentation must be available to reflect pre- and post-anesthetic evaluations as well as intraoperative monitoring.

MAC provided by qualified anesthesia personnel may be reimbursed for these procedures only when one or more of the following conditions are met:

1. It qualifies for use of HCPCS modifier QS:

• Combative patients
• Patients with low pain thresholds or who experience severe pain
• Situations where the surgeon anticipates the possible intra-operative expansion of a procedure
• Any condition in a Medicare eligible pediatric patient less than 12 years of age
• The patient has a physical status grade of P3 or higher noted in the medical record
• This modifier may only be submitted with anesthesia procedure codes (i.e., CPT codes 00100–01999)
• Submit HCPCS modifier QS to indicate that the anesthesia service performed as monitored anesthesia care
• This modifier is informational only. You must report actual anesthesia time on the claim.
• Submit the HCPCS modifier indicating that the service was personally performed or involved medical direction or medical supervision first, and submit HCPCS modifier QS second

• Submit the HCPCS modifier indicating that the service was personally performed or involved medical direction or medical supervision first, and submit HCPCS modifier G8 second

• Submit the HCPCS modifier indicating that the service was personally performed or involved medical direction or medical supervision first, and submit HCPCS modifier G9 second

References

• CMS Medicare Claims Processing Manual (PDF, 1.12 MB) (Pub. 100-04), Chapter 12, Monitored Anesthesia Care 50.I
• Guidelines for the use of deep sedation and anesthesia for GI endoscopy, Gastrointestinal Endoscopy. 2002;56(5):616