Since 2006, Boston Public Schools (BPS) has been implementing expanded learning time (ELT) in schools to improve student outcomes, close opportunity and achievement gaps, and enhance preparation and planning opportunities for staff to support these efforts. In 2015, the district and the Boston Teachers Union agreed to add 40 minutes to the school day at 60 schools, known as "Schedule A ELT." From 2015 to 2017, BPS collaborated with American Institutes for Research (AIR) on IES-funded grant R305H150013 to study its ELT program types, with the goal of understanding the impact of ELT on student, staff, and parent outcomes. Looking at whether additional time alone affects student outcomes, researchers performed comparative interrupted time series (CITS) analyses to examine impacts on student performance in the first two years after ELT implementation. This handout addresses the study's statistically significant findings, which are found only for student outcomes. [For the Year 1 Findings Report, see ED621605. For the Year 2 Findings Report, see ED621607.]