Social and emotional learning (SEL) has become popular among many education scholars, policymakers, and practitioners. State and federal education agencies have signaled to educators that they value SEL-related practices and outcomes, and professional organizations' journals are increasingly filled with SEL content. SEL is typically defined as the process through which students develop interpersonal skills, such as social awareness, and intrapersonal skills, such as emotion regulation. This definition is quite broad, and educators have access to a mind-boggling number of frameworks that list and define specific skills. How advocates choose to measure SEL will play a critical role in shaping the effort's goals and success. The lack of clarity and consensus around SEL creates a specific challenge when it comes to devising credible measures, so schools must be mindful of using instruments carefully and avoiding overreliance on formal assessments. District and school leaders should take care to solicit feedback from teachers and families about how to customize SEL measures when needed and evaluate what is and is not working. In this paper, the authors suggest how districts and schools should engage in a thoughtful process to choose SEL measures and communicate why they are doing so to teachers and families.