Which modifier is used for a CRNA's services when under medical direction?

The QX modifier is specifically utilized to indicate that a Certified Registered Nurse Anesthetist (CRNA) is providing services under the medical direction of a physician. When billing for anesthesia services, this modifier is essential as it signifies that the CRNA's practice involves a collaborative model with a supervising physician, which allows for proper reimbursement and adherence to regulatory requirements.

Employing the QX modifier communicates to payers that the CRNA's services are not being performed independently but rather as part of a directed anesthesia service, where the physician overseeing the anesthetic care has certain supervisory responsibilities. This distinction is important in the context of Medicare and other insurance reimbursements, as it helps to outline the relationship and billing protocols between the CRNA and the supervising physician.