The amount of language input bilingual children receive influences their language acquisition. This three-year quasi-longitudinal study determined the extent home language input influences measures of expressive and receptive English vocabulary among Spanish-English school-age bilingual children. The study also determined whether a relationship exists between school of attendance and measures of expressive and receptive English vocabulary among the same group of children. One Spanish-English dual-immersion school and one English-only school in Utah participated in the study. Participants were administered two formal measures of receptive and expressive English once a year for three consecutive years. Results indicate that regardless of their home language, all children demonstrated improvements in receptive and expressive English language skills after three years. Between year one and three, the increase in English receptive language measures were statistically significant among the children who primarily heard Spanish at home. Results revealed that all children made advancements in expressive and receptive vocabulary skills, regardless of their home language and the type of school they attended. Findings suggest that exposure to a language other than English at home is not a detriment to English language development. Additionally, bilingual education is as effective as English-only education in fostering children's vocabulary skills in English.