While certain components of the medical home model have been shown to improve health care and reduce costs, few evaluations have been done to demonstrate the benefits of the model overall—and none have involved the majority of the payers in a given state. This project will evaluate the impact of a public–private, multipayer medical home demonstration in Rhode Island, under which public and private health plans serving the majority of the state's insured population have agreed to support core services of the patient-centered medical home. Five large physician practices will receive assistance in providing this enhanced care, as well as a monthly supplemental case rate payment per patient. The project team will determine whether the Rhode Island model is effective in transforming these practices into medical homes, and whether it improves the quality of care, patients' care experiences, and total costs.