The Massachusetts Expanded Learning Time (ELT) initiative was established in 2005 with planning grants that allowed a limited number of schools to explore a redesign of their respective schedules and add time to their day or year. Participating schools are required to expand learning time by at least 300 hours per academic year to improve student outcomes in core academic subjects, broaden enrichment opportunities, and improve instruction by adding more planning and professional development time for teachers. Schools draw upon state resources as well as technical assistance and support from Massachusetts 2020 (Mass 2020) and Focus on Results to implement expanded learning time in their schools. The first cohort of ten ELT schools (Cohort 1) received implementation grants to begin operating their expanded days in the 2006-07 school year; in 2007-08, a second cohort of nine schools (Cohort 2) began to implement ELT; and a third cohort of nine schools began in 2008-09, resulting in an initial group of 26 ELT schools in the Commonwealth. There has not been additional funding for new ELT schools since then. In the most recently completed school year, 2010-11, 19 schools continued to implement the initiative. Abt Associates Inc. is completing a multi-year evaluation of ELT that examines both the implementation of ELT in the funded schools, and the outcomes for schools, teachers, and students hypothesized to result from effective ELT implementation. This report describes current implementation and outcomes for an initiative that has been underway for five full academic years. The staggered nature of the ELT initiative means that as of the end of the 2010-11 school year, participating schools have completed five, four, and three years of implementation (Cohorts 1, 2, and 3, respectively). Appendices include exhibits for chapters 1-5. [This report was written with assistance from: Stephanie Althoff, Beth Boulay, David Bell-Feins, Mieka Lewis, Alyssa Rulf Fountain, Missy Robinson, and Fatih Unlu.]