Nearly 25 percent of the students attending California's K-12 public schools are English Learners (ELs). Their EL designation is intended to last only as long as they need supplemental language support to succeed in school. Because outcomes for students reclassified as English proficient are much better than for students who remain ELs, policymakers are seeking answers to questions about how quickly EL students should be reclassified, whether reclassification criteria should be standardized, and the links between reclassification and academic success. This report examines reclassification policies and the academic performance of ELs and former ELs in the two largest school districts in California, Los Angeles Unified and San Diego Unified, which together serve approximately 15 percent of the state's EL students. The report uses longitudinal student data over ten years, to follow students from 2nd grade through their 12th grade year. [The authors acknowledge additional research support from Joseph M. Hayes. For the Technical Appendices, see ED561952.]