Funding from the Race to the Top-Early Learning Challenge (RTT-ELC) grant has allowed Massachusetts an unprecedented opportunity to accelerate early childhood education so that the states' children have access to high quality early education that will put them on an early path to school success and productive citizenship. The Massachusetts Department of Early Education and Care (EEC), the lead agency for the RTT-ELC grant, set an ambitious agenda to improve early learning through the following goals: (1) improving the quality of early learning programs through increased participation in the state's Quality Rating and Improvement System (QRIS); (2) establishing a seamless system of developmentally appropriate learning and development standards for children from birth to third grade; (3) implementing comprehensive assessment practices through developmental screenings and formative assessment to measure children's growth; (4) engaging families and local communities to support children's school readiness, in particular early literacy, STEM education and social-emotional learning; (5) supporting early educators to increase their knowledge, skills and competencies in order to provide high quality learning experiences for children; and (6) building infrastructure to systematically support early learning through enhanced IT capabilities and cross-sector collaborations. This report provides a summary of the accomplishments and successes achieved by Massachusetts from 2012 to 2016 as part of the RTT-ELC grant period, including the one year no-cost extension period.