The broad goal of this study is to assess the effectiveness of two interventions to facilitate treatment linkage and treatment engagement. "Treatment linkage" is operationally defined as completion of agency intake procedures and attendance at the first clinical or therapy session. "Treatment engagement" represents a more comprehensive conceptualization of "treatment retention" and includes measures of the clinical and ancillary services actually received by the client over time; as such, client engagement focuses on the intensity and duration of treatment participation. This study will enhance the CIU concept by conducting a controlled trial, using a three-armed research design, of interventions designed to enhance treatment linkage and treatment engagement. These interventions - a Motivational Intervention and Strengths-Based Case Management - are science-based and have demonstrated efficacy in moving drug abusers towards treatment and supporting treatment engagement.