For billing purposes, CRNA and AA services are considered either
medically directed or
medically supervised. AAs must work under the medical direction of an anesthesiologist who is physically present during the provision of services. CRNAs may be either medically directed by an anesthesiologist or medically supervised by the attending physician.
Providers should indicate whether a procedure was medically directed or medically supervised by using an appropriate modifier following the procedure code.
Medically Directed Anesthesia Services
Medically directed anesthesia services are those services performed by a CRNA or an AA and directed by an anesthesiologist. When a CRNA or AA is medically directed, the anesthesiologist must do
all of the following:
- Perform pre-anesthesia examination and evaluation.
- Prescribe the anesthesia plan.
- Personally participate in the most demanding procedures of the anesthesia plan, including induction and emergence, if applicable.
- Monitor at frequent intervals the course of anesthesia administered.
- Remain physically present and available for immediate diagnosis and treatment of emergencies.
- Indicate post-anesthesia care.
Medically Supervised Anesthesia Services
Medically supervised anesthesia services are those services performed by a CRNA and supervised by the attending physician. When a CRNA is medically supervised, the attending physician:
- Reviews and verifies the pre-anesthesia evaluation performed by the CRNA.
- Reviews the anesthesia plan, including medication.
- Reviews and comments during pre-anesthesia care.
- Reviews and comments during post-anesthesia care.
Medically Directed vs. Medically Supervised Anesthesia Services
For medically directed anesthesia services, an anesthesiologist is present during critical points in the procedure and is immediately available for diagnosis and treatment of emergencies. However, when a CRNA is medically supervised by the attending physician, an anesthesiologist does not have to be present during critical points in the procedure or immediately available for diagnosis and treatment of an emergency.
AAs must perform services under the medical direction of an anesthesiologist. Therefore, they
cannot perform medically supervised anesthesia services.