This case study describes the process of translating efficacy-based Diabetes Prevention Program principles into a practical format for delivery within a managed care organization. Using Rogers' innovation-decision process model, the authors tracked the adoption, implementation, and short-term effectiveness of a clinical program. Effectiveness was documented using a pre-post design to detect changes in physical activity and dietary habits. Participants (N = 298) were Kaiser Permanente of Colorado patients enrolled in diabetes-prevention classes. Changes were analyzed using paired-samples t tests and one-way analysis of variance. Participants significantly increased reported minutes of moderate (p < .001, mu = 84.52, CI: 58.44-110.61) and vigorous (t = 2.220, p = .028, mu = 19.05, CI: 2.10-36.00) physical activity and their daily servings of fruits and vegetables (p < .001, mu = 0.20, CI: 0.13-0.27). By identifying the underlying strategies that led to efficacy, professionals can implement sound diabetes-prevention programs that fit within their context.