The CORE districts have been measuring SEL via self-report student surveys since 2015. Any district, state, or school looking to use these surveys can now build from what we have learned in the CORE districts. In this paper we provide benchmarking data, including means and standard deviations by construct, grade level and subgroup, and examples of how to use these data in practice. The data come from nearly half a million students across the 8 CORE districts, in grades 4 through 12, who took the survey in the 2015-16 school year. While not a true national sample, the CORE benchmarking sample is large and diverse enough to serve as a proxy for a nationally-normed sample. As such, it can provide comparative data for other schools across the country that choose to administer the CORE districts’ survey.