During a study of Higher Achievement that began in 2015 — described below — the program operated an Afterschool Academy three days a week (3:30 p.m. to 7:30 p.m.) for 25 weeks during the school year, as well as a six-week, eight-hour-a-day summer program called the Summer Academy. The program was proven effective in a rigorous evaluation of the flagship site, DC Metro (Washington, DC, and Alexandria, Virginia), conducted in the mid-2000s. Starting in 2009, Higher Achievement expanded to three new cities: Baltimore, Maryland, in 2009; Richmond, Virginia, in 2011; and Pittsburgh, Pennsylvania, in 2012. Keenly aware that many effective flagship programs fail to stay effective when they expand, the U.S. Department of Education funded a validation study of Higher Achievement in 2015 to examine whether students’ academic performance was positively impacted at the expansion sites and whether a promising program can be scaled up and remain effective. MDRC, in collaboration with the authors of the first study of Higher Achievement, began the validation study in 2015. This report documents that study’s findings. (author abstract)