Background/Context: Relying largely on high school measures of home language use, the literature examining immigrant incorporation in schools provides contradictory evidence of home language effects on educational outcomes. More recent research has demonstrated that home language use is dynamic and thus it is important to examine the implications of elementary school home language, as opposed to the typically used high school home language, as a factor influencing various school processes. We argue that it is also necessary to take into account school-related language contexts when considering the experiences of Latino immigrant students. Purpose: This study investigates the effects of early acculturation, measured by elementary school language, immigrant generation, and early linguistic experiences on high school completion. Research Design: Using hierarchical generalized linear models, we test the effects of elementary home language, immigrant generation, early language classification, and middle school concentration of English Learners (EL) on the probability of high school completion for a cohort of Latino students in a large urban school district (N = 26,487). Findings: Consistent with some of the existing research, this study finds that speaking Spanish at home in the elementary school years has positive effects on high school completion. Moreover, for Spanish speakers, having been reclassified as English-fluent before sixth grade and having attended middle schools with lower concentrations of EL students increases the probability of high school completion. Conclusions: These findings suggest that taking into account earlier schooling processes and contexts in discussions about the influence of home language on academic achievement broaden the scope of accountability for educating immigrant students.