The 2013 CASEL Guide identifies well-designed, evidence-based social and emotional learning programs with potential for broad dissemination to schools across the United States. Based on CASEL’s work in research and practice spanning nearly two decades, we provide a systematic framework for evaluating the quality of classroom-based social and emotional learning (SEL) programs. In addition, the Guide shares best practices for district and school teams on how to select and implement social and emotional learning programs.