City Year is a learning organization committed to the rigorous evaluation of its "Whole School Whole Child" model, which trains and deploys teams of AmeriCorps members to low-performing, urban schools to empower more students to reach their full potential. A third-party study by Policy Studies Associates (PSA) examined the impact of "Whole School Whole Child" on City Year's partner schools' performance in comparison to similar schools without City Year. This study used publicly available data that local education agencies (LEAs), State and U.S. Departments of Education use to assess school performance. PSA found that schools with teams of City Year AmeriCorps members were two to three times more likely to increase English Language Arts (ELA) and math proficiency rates compared with similar schools that did not partner with City Year, as measured by state assessments. Schools that partnered with City Year also gained the equivalent of approximately one month of additional learning in math and ELA. PSA used a methodology common in education and social science research--a quasi-experimental comparison group study--of City Year's impact on its partner elementary, middle and high schools in 22 cities over three school years, from 2012 to 2014. This study was designed to estimate the impact of City Year's holistic "Whole School Whole Child" model during the first three years of its national implementation. City Year first piloted the "Whole School Whole Child" model in 2007 and, by 2011-2012, had achieved greater consistency in its implementation and in the collection of student data. The model is designed to build community-based learning environments that foster the academic and social emotional mind-sets and competencies essential to sustained student performance, and includes school climate work, whole class support,targeted one-on-one and small group tutoring in literacy and math, attendance interventions, social and emotional learning supports, and after school programming. More than 93% of the schools partnered with City Year are high-poverty (i.e. serve populations in which 75% or more students are classified as economically disadvantaged). The findings of this study suggest that City Year's "Whole School Whole Child" model generates positive results for its partner elementary, middle, and high schools. The following are appended: (1) High Performing City Year Partner Schools; (2) Data Sources and Regression Models; and (3) Coding Method for Binary Outcome Variables Used in the Logistic Regressions.