<p>Studies of program components (i.e., the ingredients that make up programs) have risen from obscurity to join mainstream program evaluation approaches over the last two decades. Researchers and policymakers are interested in leveraging information about the effectiveness of program components to better address the needs of programs’ intended populations and reduce disparities in outcomes. Identifying which components are responsible for improving outcomes can inform evaluation design, measurement, and the state of the evidence as well as program development, adaptation, fidelity, and scale-up. This paper summarizes strategies for conducting components research, and anchors those emerging best practices in a components case study of a teen pregnancy prevention program. It offers applied guidance on ways to define and operationalize components, and best practices in measurement and analysis that have emerged from this work. This paper will help guide the prevention field toward conducting more and better research that yields consensus about which components are most important for program effectiveness.</p>