This College Success Research Brief is one of a series of briefs documenting the implementation and impact of Mass Insight's College Success/STEM program. The research briefs are intended to share key findings, highlight ongoing questions and lines of inquiry, and inform the thinking of practitioners and policymakers on how to scale up efforts to accelerate improvements in districts and schools, focusing on college readiness and success. This research brief provides updated evaluation findings documenting the extent to which Mass Insight students--those students taking at least one Advanced Placement® math, science, or English course in high school--are attending and persisting in college. Building upon the "Achieving College Success" report, this report provides comprehensive data on Mass Insight students who graduated from high school in 2009, 2010, or 2011, representing 4,997 students across 45 schools. The brief also includes the appendices: (1) Theory of Action guiding the College Success/STEM program, (2) Methodology for developing comparison groups, and (3) Data.