During the summer, children from low-income families typically have fewer opportunities than their peers from more-affluent families for academic, cultural, athletic, and other activities. Such differences in opportunity can lead low-income students to fall behind their higher-income peers during summer. Free summer learning programs offering academic and enrichment activities provided by school districts can help address this opportunity gap. To support such programs, The Wallace Foundation launched the National Summer Learning Project (NSLP) in 2011. The NSLP has provided financial support and technical assistance to the public school districts and their community partners in Boston, Massachusetts; Dallas, Texas; Duval County, Florida; Pittsburgh, Pennsylvania; and Rochester, New York to facilitate the offering of voluntary, district-led summer learning programs at no cost to low-income students in urban elementary schools. As NSLP funding drew to a close in 2017, districts and their community partners focused on sustainability efforts to continue providing and, to the extent possible, to scale up high-quality summer programs for students. These efforts demonstrated the need for summer program leaders to navigate and shape policies at the district, city, state, and federal levels to support the scale, sustainability, and quality of their programs. The Wallace Foundation asked RAND to help shed light on the policy landscape by addressing one question: How do district, city, state, and federal policies support and constrain the scale, sustainability, and quality of district-provided summer learning programs? In this brief, the authors summarize the main findings and conclusions and offer recommendations for district-based summer program leaders.