Clinical practice guidelines must be implemented effectively if they are to influence the behavior of clinicians. The authors describe a model for computer-based guideline implementation that identifies eight information management services needed to integrate guideline-based decision support with clinical workflow. Recommendation services determine appropriate activities in specific clinical circumstances. Documentation services involve data capture. Registration services integrate demographic and administrative data. Explanation services enhance the credibility of automated recommendations by providing supportive evidence and rating the quality of evidence. Calculation services measure time intervals, suggest medication dosages, and perform other computational tasks. Communication services employ standards for information transfer and provide data security. Effective presentation services facilitate understanding of complex data, clarify trends, and format written materials (including prescriptions) for patients. Aggregation services associate outcomes with specific guideline interventions. The authors provide examples of the eight services that make up the model from five evidence-based practice parameters developed by the American Academy of Pediatrics.