Statement on Distinguishing Monitored Anesthesia Care ("MAC") from Moderate Sedation/Analgesia (Conscious Sedation)

Developed by: Committee on Economics
Original Approval: October 18, 2023

Moderate Sedation/Analgesia (Conscious Sedation; hereinafter known as Moderate Sedation) is a service recognized in the CPT procedural coding system. During Moderate Sedation, a qualified provider supervises or personally administers sedative and/or analgesic medications such that the patient responds purposefully to verbal commands, either alone or accompanied by light tactile stimulation. This can allay patient anxiety and limit pain during a diagnostic or therapeutic procedure. During Moderate Sedation, the responsible provider typically assumes the dual role of performing the procedure and supervising the sedation. Such drug-induced depression of a patient’s level of consciousness to a “moderate” level of sedation, as defined in the Centers for Medicare & Medicaid Services Conditions of Participation, is intended to facilitate the successful performance of the diagnostic or therapeutic procedure while providing patient comfort and cooperation. Those providing moderate sedation must be qualified to recognize “deep” sedation, manage its consequences, and adjust the level of sedation to a “moderate” or lesser level. The continual appraisal of the effects of sedative or analgesic medications on the level of consciousness and on cardiac and respiratory function is an integral element of this service. 

The American Society of Anesthesiologists has defined Monitored Anesthesia Care (MAC) as a specific anesthesia service performed by a qualified (trained) anesthesia provider, for a diagnostic or therapeutic procedure. Indications for MAC include, but are not limited to, the nature of the procedure, the patient’s clinical condition and/or the need for deeper levels of analgesia and sedation than can be provided by moderate sedation (including potential conversion to a general or regional anesthetic). Monitored Anesthesia Care includes all aspects of anesthesia care—a preprocedure assessment and optimization, intraprocedure care and postprocedure management that is inherently provided by a qualified anesthesia provider as part of the bundled specific service. During MAC, the anesthesiologist provides or medically directs a number of specific services, including but not limited to: 

• Preprocedural assessment and management of patient comorbidity and periprocedural risk
• Diagnosis and treatment of clinical problems that occur during the procedure 
• Support of vital functions inclusive of hemodynamic stability, airway management, and appropriate management of the procedure induced pathologic changes as they affect the patient’s coexisting morbidities
• Administration of sedatives, analgesics, hypnotics, anesthetic agents, or other medications as necessary for patient safety 
• Psychological support and physical comfort 
• Provision of other medical services as needed to complete the procedure safely
• Postoperative medical and pain management

MAC may include varying levels of sedation, awareness, analgesia and anxiolysis as necessary. The qualified anesthesia provider of monitored anesthesia care must be prepared to manage all levels of sedation up to and including general anesthesia and respond to the pathophysiology (airway and hemodynamic changes) of the procedure and patient positioning. Please also refer to ASA’s Statement on Continuum of Depth of Sedation: Definition of General Anesthesia and Levels of Sedation/Analgesia.

Monitored Anesthesia Care can be distinguished from Moderate Sedation in several ways. Proceduralists providing moderate sedation may have their attention divided between their primary focus, the procedure, and secondary focus, patient sedation. Moderate Sedation is not expected to induce depths of sedation that would impair the patient’s respiratory or cardiovascular functions or ability to maintain airway integrity. A provider’s ability to intervene to rescue a patient’s airway from any sedation-induced compromise is a prerequisite to the qualifications to provide MAC. These components of MAC are unique aspects of an anesthesia service that are not part of Moderate Sedation. In addition, MAC includes an array of post-procedure responsibilities beyond the expectations of practitioners providing Moderate Sedation, including assuring a return to baseline consciousness, relief of pain, management of adverse physiological responses or side effects from medications administered during the procedure, as well as the diagnosis and treatment of co-existing medical problems.

Monitored Anesthesia Care allows for the safe administration of a depth of sedation in excess of that provided during Moderate Sedation. The ability to adjust the sedation level from full consciousness to general anesthesia during a procedure provides maximal flexibility in matching sedation level to a patient’s needs and procedural requirements. In situations where the procedure is more invasive, or when the patient is especially fragile, optimizing sedation level while maintaining cardiopulmonary function is necessary to achieve ideal procedural conditions. 

In summary, MAC is an anesthesia service that is clearly distinct from Moderate Sedation due to the expectations and qualifications of the provider who must be able to utilize all anesthesia resources to support life and to provide patient comfort and safety during a diagnostic or therapeutic procedure. Monitored Anesthesia Care should be subject to the same level of payment as general or regional anesthesia. Accordingly, the ASA Relative Value Guide® provides for the use of proper base units, time units, and any appropriate modifier units as the basis for determining payment.