The goal of this project is to extend the evaluation of Maryland’s Pre-Kindergarten Expansion program, which is employing a Regression Discontinuity Design to determine the benefits of the PreK program on low-income children in Baltimore City Public Schools. The specific aims of the Brady-funded project are: 1) to examine the moderating role of family factors (including protective factors) in the impact of PreKindergarten on participant children; and 2) to explore if and how the Pre-Kindergarten experience buffers children against the impact of toxic stress. To this end, we will collect data in children’s homes to learn more about the contexts in which they are reared. Specifically, we will interview parents to obtain information on family demographics, parental physical and mental health, and family structure and processes, as well as observe parenting processes and the home environment. This project is consistent with the mission of the Brady Education Foundation in that it examines efforts to reduce the achievement gap between low-income children and their more advantaged peers, and addresses the environmental factors associated with poverty. The Principal Investigator is Brenda P. Jones Harden, Ph.D., of the University of Maryland.