Since 2012, the Research Alliance for New York City Schools has been conducting an evaluation of the Expanded Success Initiative, a New York City Department of Education initiative designed to increase college and career readiness among Black and Latino male students. The Expanded Success Initiative provides funding and professional development to 40 New York City high schools that were selected to participate based on an application process and eligibility criteria designed by the district. Our evaluation was designed to assess both the implementation and the roll-out of Expanded Success Initiative across the 40 participating schools and to measure the impact of Expanded Success Initiative on a variety of post-secondary readiness outcomes. The evaluation is a 4-year evaluation, and we are currently commencing the fourth year of the evaluation. This case study provides an overview of the evaluation design, data sources, and analytic approaches. Furthermore, it highlights the unique aspects of this evaluation research such as evaluating programming that looked quite different across 40 school sites, placing our qualitative and quantitative data in conversation with each other, and collaborating with the New York City Department of Education to improve our evaluation methods and provide formative feedback to the central Expanded Success Initiative team at New York City Department of Education, which was responsible for the roll-out of the initiative.