The goals of the National Institute on Drug Abuse Clinical Trials Network (CTN) are to test promising drug abuse treatment models in multisite clinical trials and to support the adoption of new interventions into clinical practice. Using qualitative research methods, we studied adoption in the context of two multisite trials, one outside the CTN and another within the CTN. Seventy-one participants representing eight organizational roles ranging from clinic staff to clinical trial leaders were interviewed about their role in the clinical trial, the trial's interactions with clinics, and intervention adoption. Drawing on the conceptual themes identified in these interviews, we report on strategies that could be applied in the planning, development, and implementation of multisite studies to better support the adoption of tested interventions in study clinics after trials had ended. Planning for adoption in the early stages of protocol development will enhance the integration of new interventions into practice.