This article presents findings from qualitative research conducted in eight New York City public schools offering English as a new language (also known as English as a second language), in which language education policies were monolingual in English at the start of data collection. These schools participated in an intensive professional development and technical assistance project for which they were required to engage students' bilingualism as a resource in instruction and implement translanguaging pedagogy, using the entire linguistic repertoire of bilingual children flexibly and strategically in instruction (García, Ibarra Johnson, & Seltzer, 2016). This study documents the efforts of participating schools to make their practices for emergent bilinguals more multilingual. Findings suggest that translanguaging pedagogy initiated broader ideological shifts as educators adopted a translanguaging stance that has proven transformative to the schools as a whole. Specifically, findings reveal changes in how educators thought about emergent bilinguals, their language practices and the place of those practices in instruction, and how this ideological shift engendered significant changes in several schools to their language policies. Moreover, findings show how the introduction of translanguaging pedagogy in participating schools disrupted dominant monolingual approaches in theoretical and practical ways and the impact of doing so on educators and students.