In this study, we investigate the relationship between the utilization of advanced practice providers (APPs) and the quality performance of medical practice groups as measured by the Merit-based Incentive Payment System score assessed by the United States Centers for Medicare and Medicaid Services. APPs, who are primarily physician assistants and nurse practitioners, are non-physician healthcare providers who can perform many of the same tasks as physicians. Their increased use has been suggested as a means of improving cost and access of healthcare in the United States, but there is a question of whether quality of care would be affected. In contrast to most results from prior research, we find that the utilization of APPs is negatively related to quality performance. We discuss the implications of these findings for research and practice.