This paper presents evidence of the effects of dual language immersion (DLI) programs on the academic outcomes of students in elementary grades. Leveraging enrollment lotteries from four cohorts of DLI applicants across 10 oversubscribed programs, analyses estimate the intent-to-treat effect of access to bilingual education on reading and math test scores. On average, native English-speaking students in Grades 1 through 4 who win access to a DLI program score higher in reading and math by 0.12 and 0.14 SDs, respectively. The achievement gains in test scores are realized as early as first grade.