In the past decade, there has been a proliferation of community- and school-based college readiness programs designed to increase the participation of students who have traditionally been underrepresented in higher education. However, few of these college readiness programs have been empirically evaluated. This study examines the impact of one such intervention, the College Bound, St. Louis (CB) program. Using propensity weighting and doubly robust modeling, we found CB participants were more likely to reach proficiency on the End of Course exams, to obtain at least a B grade in a number of foundational college courses, to take more AP or honors courses, and to attend a 4-year postsecondary institution than similarly situated non-participants. Future directions for evaluating similar college readiness programs are discussed.