Family members and professionals in a Substance Abuse and Mental Health Services Administration Children's Mental Health Systems of Care Initiative in Houston, Texas conducted a participatory evaluation to examine wraparound implementation. Results guided systematic, theory-based program revisions. By focusing through empirically derived frameworks for implementation, the evaluation team identified and generated useful data sources to support and improve wraparound provision. Despite working with a more diverse population in which youth displayed more severe behaviors than in similar grants, after 18 months more families received service and outcomes improved as fidelity scores advanced above the national mean.