Three common staffing models for delivering anesthesia exist in the United States: services delivered by anesthesiologists only, services delivered by certified registered nurse anesthetists (CRNAs) only, and services delivered by anesthesiologist and CRNA teams. Given the opt-out policy enacted by the Centers for Medicare & Medicaid Services in 2001, it is reasonable to expect that the use of CRNAs would vary by state opt-out status. Allowing CRNAs to provide anesthesia services independently may help alleviate perceived anesthesiology provider shortages, particularly in rural locations, without adversely affecting patient quality of care while reducing total anesthesia delivery costs.