This report explores summer learning programming in three sites run by the BELL (Building Educated Leaders for Life) organization. It finds that the five-week remedial programs, which provided morning academics and afternoon enrichment for middle school students, were well run and well staffed. The children — many of them low academic performers and most of them from low-income families — attended at high rates even though enrollment was not mandatory. One of the few studies to examine the impact of summer programs on middle schoolers, the study also tried to assess the program’s effect on student learning. The research involved random assignment, the most rigorous approach, but encountered difficulties, including recruiting too few students to result in an investigation with sufficient statistical “power.” The report’s discussion of these challenges could prove instructive for other nonprofits considering randomized controlled trials. Because of these difficulties, the study’s effects findings are not definitive. They offer preliminary evidence that BELL’s programs could have a positive effect on middle school student math achievement and that improving reading achievement is more challenging.