The current study, implemented during the 2017-18 and 2018-19 school years, sought to examine teacher practices in support of EMLs in New York City Universal Prekindergarten (UPK) classrooms, as well as workforce characteristics and professional learning opportunities provided to UPK teachers and program leaders. Using structured, direct observations of 50 UPK classrooms, we examined: (1) the quality of teacher-child interactions in terms of emotional support, classroom management, and instructional support, measured by the Classroom Assessment Scoring System (CLASS), and (2) the extent to which teachers nurtured a culturally and linguistically responsive environment and supported EMLs’ acquisition of English and home language, measured by the Classroom Assessment of Supports for English Language Acquisition (CASELA). Additional survey data was collected to examine workforce characteristics and professional supports related to preparation, professional development, and ongoing job-embedded support. (author abstract)