<p>Given the large and persistent wage gaps between those with college degrees and those without, increasing the pool of college-educated workers remains a critical public policy objective. Many students–particularly those from lower-income households and those whose family members did not attend college–face numerous barriers to college entry and college success should they enroll. Therefore, efforts to help historically underserved students succeed in higher education hold considerable promise for expanding the pool of students attending and persisting in college. In this paper, we use regression-discontinuity analysis to examine one such program, called the Summer Success Academy (SSA). Using school administrative data from 2012–2017 to evaluate the impact of program participation on students’ GPA and persistence in college, we find that participation in the SSA results in a significant positive effect on persistence, and that the effect is particularly strong for students who are eligible for Pell Grants. We do not find evidence that students in the program achieve higher grade point averages in college. The results suggest that even a relatively short summer support program can significantly improve persistence in college among historically underserved students.</p>