This study investigated the degree to which the quality of teachers' language modeling contributed to reading achievement for 995 students, both English language learners and native English speakers, across developmental bilingual, dual language, and monolingual English classrooms. Covariates included prior reading achievement, gender, eligibility for free lunch, and ethnicity. A 2-level hierarchical linear modeling analysis revealed that (a) prior achievement, Latino ethnicity, and eligibility for free lunch contributed significantly to the model but gender did not; (b) students gained 3 points for each unit increase in the quality of language modeling across classrooms; and (c) reading achievement for English language learners was not significantly different than that for native English-speaking students. In addition, cross-level interactions revealed that the slope of the quality of language modeling and reading achievement for students in monolingual English classrooms and developmental bilingual classrooms was stronger than that for students in dual language classrooms. We discuss classroom implications of bilingualism and language modeling in improving reading outcomes.