Most research on managed mental health care has focused on its direct clinical and fiscal impacts on mental health services. However, its impacts on other systems remain largely unknown. These potential intersystem effects are especially important as a large number of persons with mental health services needs are detained in jails, and jail detention rates continue their astronomical rise. This proposal presents a research plan for a three-year longitudinal study (2002-2005) of the impact of Medicaid capitation on the use of multiple systems of rare in King County (Seattle) Washington. This is the first comprehensive, population based effort to assess the inter-system impacts of managed behavioral health care and cost shifting from behavioral health to local jails. In a preliminary study, we obtained records on 50,000 King County residents from 1993-1998. To assess the effects of capitation, we will gather additional data on this same (prevalence) cohort, plus an additional 50,000 new subjects for the five-year time period of 1999-2003. These additional cohorts will be selected from the Medicaid enrollment records, jail detention records, and mental health utilization records, and will use our previous methodology that over-samples subjects who have records in multiple systems. As we have done before, we propose to draw electronic utilization records maintained by six different state and local agencies, that will include utilization records from mental health providers, substance abuse providers, jails and jail based clinicians, general hospitals, and general Medicaid providers. Analyses will consist of econometric modeling and hierarchical regressions and multinumeral logits to assess the impact of managed care on overall trends, intersystem service use, and cost-shifting. Findings will be targeted to a variety of local and national audiences concerned about improving care for the various population groups involved.