Anesthesiologist Assistants (AAs)

For information on how to enroll in Medicare, visit Advanced Practice Nonphysician Practitioners.

You must:

• Work under anesthesiologist's direction
• Comply with all applicable state laws, including state licensure requirements imposed on non-physician anesthetists
• Have graduated from a medical school-based anesthesiologist assistant (AA) education program:
  • Is accredited by the Commission on Accreditation of Allied Health Education Programs
  • Includes approximately 2 years specialized science and clinical anesthesia education at a level that builds on a premedical undergraduate science background

You must meet these requirements:

• You’re legally authorized to perform anesthesia and related care in the state where you provide the services

• In a hospital, you provide services under the supervision of an anesthesiologist who’s immediately available, if needed. Immediate supervision means an anesthesiologist is physically located within the same area as the AA and can provide immediate hands-on intervention.

• In a critical access hospital or ambulatory surgical center (ASC), you provide services under the supervision of an anesthesiologist.

• You may bill for your services using:
  • Your NPI
  • The hospital, physician, group practice, or ASC NPI where you have an employment or contractor relationship
• Anesthesia time is the continuous period that:
  • Begins when you’ve prepared the patient for anesthesia services in the operating room or equivalent area
  • Ends when you place the patient safely under post-operative care
• You may add blocks of anesthesia time if you provide continuous anesthesia care within the time periods around an interruption
• Anesthesia billing modifiers include:

  • QS: Monitored anesthesia care service

    Note: A physician or qualified non-physician anesthetist may use the QS modifier for informational purposes. You must report actual anesthesia time and 1 payment modifier on the claim.

  • QX: CRNA service: with medical direction by a physician

  • QY: Medical direction of 1 certified nurse anesthetist (CRNA) by an anesthesiologist

    Note: Used by supervising physician.

  • QZ: CRNA service without medical direction by a physician

• Medicare pays only on an assignment basis
• We pay services at 100% under the Physician Fee Schedule (PFS) or in accordance with the level of supervision provided
• Under the Anesthesia Fee Schedule based on applicable locality adjusted anesthesia Conversion Factor (CF) multiplied by the sum of allowable base and time units; 1 anesthesia time unit = 15 minutes anesthesia time
• The patient may be responsible for paying you for a Part B copayment, deductible, or coinsurance
• You may bill your services directly or have payment made to a person or entity (like a hospital, CAH, physician, group practice, or ASC) if you have an employment or contractor relationship providing payment made to you or an entity

• Services, billing, and payment information: Medicare Claims Processing Manual, Chapter 12, sections 50 and 140 (PDF)
• AA qualifications: 42 CFR 69
• Anesthesiologists Center