This three-article dissertation examined how policy choices in three key policy areas -- initial enrollment, service provision, and reclassification -- impact English learner (EL)-classified students. The first article examined the national landscape of state statutes, regulations, and state education agencies' (SEA) guidance that support districts in implementing procedures to award credit to secondary newcomer students for prior learning experiences. The findings reveal a lack of education statutes and regulations, and limited implementation guidance from SEAs to support newcomer credit transfer. The second article zooms into Portland Public Schools in Oregon and examines the causal effect of the district's dual language immersion (DLI) program. The study found significant positive effects of the DLI program, demonstrating a notable increase in credit accrual, high school graduation rates, and attainment of the Seal of Biliteracy among participating students. The third article investigates the causal impact of reclassification from EL services in 5th and 8th grade on high school graduation and the mediating role of course access. The study does not identify significant effects of reclassification and does not find evidence supporting the hypothesis that early access to English Language Arts and Algebra 1 mediates the potential impact of reclassification. Findings from this dissertation contribute novel evidence to EL education policy and highlight how policy decisions at different entry points can potentially shape student outcomes. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]