Three-year funding is sought to track the impact of a capitation model designed to serve Medicaid clients in the City of Philadelphia. The Philadelphia capitation demonstration began July 1988, supported through a Robert Wood Johnson Foundation grant. The RJW grant will cover the administrative costs of converting the City's system of financing and managing mental health services to its Medicaid clients, particularly for high users of services and the seriously mentally ill (CMI) clients. The proposed research will provide a detailed documentation of the Philadelphia capitation experiment, ascertaining the impact of this new financing system on the Medicaid client population. Integrated longitudinal files on a large sample of clients will be assembled and analyzed to provide intracity comparisons between a group whose services are paid under capitation and a control group of Medicaid clients not directly subject to the experiment. Although the study is structured in a quasi-experimental framework it is intended as a systems analysis of the impact of a capitation financing experiment on Medicaid mental health clients: especially the CMI and high-users of inpatient care. The relationship of the CMI to high-users is of special interest because the high users are the focus of the capitation experiment and the CMI are the focus of the RWJ program.