OBJECTIVE: Community Partners in Care, a community-partnered, cluster-randomized trial with depressed clients from 93 Los Angeles health and community programs, examined the added value of a community coalition approach (Community Engagement and Planning [CEP]) versus individual program technical assistance (Resources for Services [RS]) for implementing depression quality improvement in underserved communities. CEP was more effective than RS in improving mental health-related quality of life, reducing behavioral health hospitalizations, and shifting services toward community-based programs at six months. At 12 months, continued evidence of improvement was found. This study examined three-year outcomes. METHODS: Among 1,004 participants with depression who were eligible for three-year follow-up, 600 participants from 89 programs completed surveys. Multiple regression analyses estimated intervention effects on poor mental health-related quality of life and depression, physical health-related quality of life, behavioral health hospital nights, and use of services. RESULTS: At three years, no differences were found in the effects of CEP versus RS on depression or mental health-related quality of life, but CEP had modest effects in improving physical health-related quality of life and reducing behavioral health hospital nights, and CEP participants had more social- and community-sector depression visits and greater use of mood stabilizers. Sensitivity analyses with longitudinal modeling reproduced these findings but found no significant differences between groups in change from baseline to three years. CONCLUSIONS: At three years, CEP and RS did not have differential effects on primary mental health outcomes, but CEP participants had modest improvements in physical health and fewer behavioral health hospital nights.