In simple words: This code is used when a nurse anesthetist gives you anesthesia under the direction of a doctor.

This modifier is used when a Certified Registered Nurse Anesthetist (CRNA) provides anesthesia services under the medical direction of a physician. Medical direction implies that the physician performs specific tasks and fulfills documentation requirements outlined by CMS and other payers.The physician must perform a pre-anesthesia exam and evaluation, prescribe the anesthesia plan, and personally participate in the most demanding procedures in the anesthesia plan, including induction and emergence (if applicable), ensure that any procedures in the anesthesia plan that he or she does not perform are performed by a qualified individual, monitor the course of anesthesia administration at frequent intervals, remain physically present and available for immediate diagnosis and treatment of emergencies, and provide indicated post-anesthesia care. The anesthesiologist may medically direct up to four concurrent cases.

Example 1: A patient undergoes a knee replacement surgery. A CRNA administers the anesthesia under the medical direction of an anesthesiologist, who performs the pre-anesthesia evaluation, prescribes the anesthesia plan, and is available for immediate intervention if necessary., A patient has a colonoscopy. The CRNA administers the anesthesia, and the anesthesiologist provides medical direction, overseeing the process and remaining available during the procedure., A woman gives birth via Cesarean section.A CRNA administers the epidural anesthesia under the medical direction of an anesthesiologist, who is present for the delivery and available for any emergent situations.

Documentation should clearly indicate that the anesthesia service was performed by a CRNA under the medical direction of a physician. The physician's documentation must include the pre-anesthesia examination and evaluation, the prescribed anesthesia plan, personal participation in the most demanding procedures, and documentation of frequent monitoring and availability for emergencies.The anesthesia record must support the use of medical direction, including start and end times for both the CRNA and physician.