During the school year leading up to summer 2015, summer leaders in Dallas, Pittsburgh, and Rochester made concerted efforts to integrate their summer learning programs into the core priorities and operations of the larger school district as a strategy to increase sustainability. This report examines these efforts and their impacts. The recommendations should be useful to leaders of district-led summer programs and others who support sustaining them. Data for this report are drawn from interviews, meeting minutes, and summer program and district documents. Starting in November 2015 through January 2016, the authors interviewed 62 district staff members involved in summer programming in these three districts. This report does not intend to represent all aspects of integration within each of these districts. The experiences of these districts will not necessarily correspond to experiences in other districts. The goal is to independently record and analyze their work as accurately as possible and to identify lessons that other summer leaders might find useful for improving the sustainability of their summer programs. The findings should be of interest to others who lead or support summer learning programs. The findings in this report include why the summer leaders pursued integration and the strategies they used to do so.