In the 2009-2010 school year, the Boston Public Schools (BPS) prekindergarten model (called K1) had the highest level of instructional quality of any evaluated large-scale prekindergarten in the U.S. (Weiland, Ulvestad, Sachs, & Yoshikawa, 2013). BPS K1 has proven positive impacts on children's language, literacy, mathematics, and executive function skills at kindergarten entry (Weiland & Yoshikawa, 2013). The K1 model combines two evidence-based curricula in prekindergarten classrooms--one focused on language and literacy instruction and the other on mathematics instruction--with regular coaching and training supports for teachers. Boston K1DS (K1 in Diverse Settings) was a 2.5-year pilot demonstration project to expand the nationally recognized BPS K1 model to 14 community-based preschool classrooms. This partnership between BPS, Thrive in 5, and community-based organizations (CBO) aimed to build a high quality, private- and city-funded network of early childhood pre-K classrooms to expand access for families, close the achievement gap, and improve academic outcomes for Boston children living in the Circle of Promise and East Boston. The pilot began in January 2013 and concluded in June 2015. This report summarizes the activities and findings of the project. (author abstract)