Since 2011, the John W. Gardner Center for Youth and Their Communities at Stanford University (Gardner Center) has examined school-based outcomes for San Mateo County Preschool for All (PFA) students who went on to attend elementary school in Redwood City School District (RCSD). Preschool for All was San Mateo County's high-quality preschool demonstration project, which ended in 2009. The Gardner Center has previously reported on PFA students' outcomes through kindergarten (2011 report) and first grade (2012 report). This study follows these students through third grade, providing a complete look at the Pre-K to third grade experiences of children who participated in PFA. The two prior reports focused on student outcomes within each grade level. This report is a longitudinal examination of PFA participants, tracking students' experiences across their first four years in elementary school. This study builds on a 2009 study that found that PFA graduates in San Mateo County were: (1) better prepared for kindergarten than their classmates who had not attended preschool and (2) equally ready for kindergarten as classmates with other preschool experiences. The Gardner Center study seeks to extend that knowledge of PFA students' outcomes into the elementary grades and focuses on two main questions: 1. How does the performance of PFA participants compare to other RCSD students on early elementary school outcomes? 2. Which RCSD supports are associated with stronger in-school outcomes for PFA participants? (author abstract)