Although implementation of universal social-emotional learning programs is becoming more common in schools, few studies have examined the cost-effectiveness of such programs. As such, the purpose of this article is two fold. First, we provide an overview of cost-effectiveness methods for school-based programs, and second, we share results of a cost-effectiveness analysis (CEA) of a universal social-emotional learning (SEL) program, the Social Skills Improvement System-Classwide Intervention Program (SSIS-CIP; Elliott & Gresham, 2007). Specifically, we compared the cost-effectiveness of SSIS-CIP implementation across first- and second-grade classrooms, and results indicated that second grade is the more cost-effective option for implementing the SSIS-CIP. Several considerations are discussed regarding cost-effectiveness analysis of universal SEL programs as well as the importance of using CEA results to inform programming decisions. Impact and Implications: In an era of limited resources, schools must be concerned not only with a program's effectiveness but also the costs necessary to obtain those effects. Results from a cost-effectiveness analysis of one universal social-emotional learning (SEL) program, the Social Skills Improvement System-Classwide Intervention Program, show that implementation in second grade was more cost-effective than implementation in first grade. School psychologists, administrators, and policymakers can benefit from using results of cost-effectiveness analyses to optimize available resources for SEL programs in schools.