The RAND Corporation is conducting a multiphase evaluation of the initiative, including an implementation study of the four pillars that underlie Big Lift--The Big Lift Implementation Study: Final Report--and a series of annual descriptive analyses focused on the outcomes of children who received Big Lift services. This report is the third in the series of outcome studies. The first two reports--Big Lift Participation and School Entry Indicators: Findings for the 2016-2017 Kindergarten Class and The Big Lift Descriptive Analyses: Kindergarten Readiness and Elementary School Reading Outcomes for the 2016-2017 and 2017-2018 Kindergarten Classes--focused on the early education and summer learning experiences of the 2016-2017 and 2017-2018 kindergarten classes. In this report, we continue to follow these children through elementary school and add data for a new class of children, the 2018-2019 kindergarten class. We also focus on pooling data across kindergarten classes to understand how Big Lift children compare with their peers among all children eligible for services to date. The report should be of interest to Big Lift stakeholders, including San Mateo County policymakers, educators, parents, and community members. Practitioners, policymakers, advocates, and researchers in other parts of the United States might find the information on this initiative useful for work related to the planning, implementation, or evaluation of other initiatives extending from early childhood through third grade. (author abstract)