OBJECTIVE: This study examined outcomes of clients admitted to assertive community treatment programs simultaneously implemented at six sites in northeastern Indiana. METHODS: A total of 212 clients at risk for psychiatric rehospitalization were assessed at baseline and at six-month intervals for 18 months after admission to assertive community treatment programs. Data on rehospitalization, quality of life, and level of functioning were compared using t tests. Progressive improvement was also examined by linear trend analysis. RESULTS: Frequency of psychiatric hospitalization was reduced by one-third and the number of inpatient days by 50 percent after admission to the program. Improvements were progressive, with continued reductions over the 18-month period. Progressive improvements also occurred in quality of life as measured by both client and staff ratings. Case managers rated clients as having improved family and social support, increased self-reliance and independence, and improved daily living skills. Clients reported significantly more legal problems, which may have been an artifact of increased monitoring during treatment. A key element of the programs' success was the position of clinical coordinator, important functions of which are described. CONCLUSIONS: Results of this study provide support for wide-scale dissemination of assertive community treatment as an effective form of community care for persons with serious mental illness.