One in five school-age children in the U.S. speaks a language other than English at home (Zeigler & Camarota, 2014). Roughly half of these emerging bilingual students (Garcia, 2009) are classified as English learners (ELs) when they enter school, meaning they do not meet state or district criteria for English proficiency (NCES, 2015). As the fastest growing official subgroup of students, ELs are transforming schools across the country, in cities as well as suburban and rural communities; in traditional immigrant-receiving areas as well as in new immigrant destinations. Emerging bilingual students, and the subset of them that are classified as ELs, bring with them important linguistic, social, cultural, and intellectual assets that can enrich and strengthen education for all students (González, Moll & Amanti, 2013). But questions persist around how best to ensure that students who are not yet proficient in English can thrive in school, academically, linguistically, and socially. Should ELs be taught in bilingual classrooms that promote fluency in their home language while ensuring access to core academic content and developing English language skills? Or should they be taught in English immersion classrooms in order to maximize exposure to English? How do we ensure that emerging bilingual students develop both English proficiency and strong academic skills, while maintaining and developing literacy in their home language? How can schools best build on ELs' linguistic assets and support their educational needs?