Relative to the academic year, learning rates typically slow down in the summer, especially for economically disadvantaged students. As such, various types of summer interventions have been implemented throughout the country, especially those geared toward students from disadvantaged backgrounds. This study provides an assessment of the effectiveness of HISD 2016 summer school, which the district offered both to retained students (which was required and needed for promotion) as well as promoted students (which was not required but available for summer enrichment).