Substance abuse in homeless persons is associated with multiple health risks and presents daunting challenges to agencies providing services. Proposed research with this vulnerable population is based on two previous randomized controlled studies showing an innovative behavioral day treatment's (BDT+) effectiveness in a community setting with different comparison groups. The second demonstrated superiority of abstinent contingent housing and work compared to BDT alone, while controlling for alternative explanations of treatment effectiveness. This study determines if BDT+ for dually diagnosed, homeless substance abusers can be successfully transported to a new site. It develops training materials and methods for new staff to implement BDT at the University of Texas, Houston Recovery Campus. Expected products are: treatment manual, 35mm slides, video tapes etc., and brief observation scales to assess fidelity of each transported BDT+ component. Objective criteria and methods assure BDT+ components have been implemented with measured specified fidelity. Implementation is studied via a 2 group randomized control comparison with usual care. From a population meeting criteria from previous studies, 100 each will be assigned to either BDT+ or an existing Riverside General Hospital Day Treatment (RGHDT) control. Assessments at baseline, 1, 2, 6 and 12 months use instruments and measures employed in original studies. Outcomes include alcohol and drug abuse, homelessness, employment and HIV/A1DS risk behaviors, and a cost effectiveness analysis. Successful implementation is ultimately defined by hypothesized, superior outcomes for BDT+. If BDT+ can be replicated, products and methods would permit transport to other settings. Results will provide important knowledge and technology for transporting complex psychosocial treatment and how to most effectively treat this dysfunctional population, knowledge which has important clinical, economic, public health and public housing policy implications.