The SSIS SEL Brief Scales-Student Form (SSIS SEL"b"-S) was developed to create an efficient assessment of students' social and emotional learning (SEL). Using item response theory with ratings from 800 students in Grades 3-12 from the standardization sample, 20 items were selected from the full-length SSIS SEL Rating Form - Student to maximize score information and rating efficiency. After identifying items for the SSIS SEL"b"-S, we conducted several reliability and validity analyses. These analyses provided initial support for the use of the SSIS SELb-S for low-stakes decision making contexts. As such, the SSIS SEL"b"-S holds promise for incorporating the perspectives of students ages 8-18 into assessments of their SEL competencies.