This White Paper summarizes findings from an extensive literature review that was conducted to identify the most promising models and approaches for meeting the needs of low-income children, youth, and families during the summer months. Special attention is paid to summer learning programs that serve diverse, urban low-income children and youth. Data on program participation suggest that children and youth who would stand to benefit the most from summer learning programs (i.e., children and youth who are economically disadvantaged, have low school engagement, and/or exhibit problem behavior) are the least likely to participate. This paper focuses on summer learning programs, as opposed to recreational, wilderness, or child care programs. Summer schools that focus on remediation are also not reviewed. Five types of summer learning programs are reviewed: (1) Educational/Cognitive; (2) Youth Development; (3) Career Development; (4) Health and Fitness; and (5) Multi-element. Experimental and non-experimental studies, as well informal evaluation reports and papers reporting practitioner insights, were reviewed to identify effective and promising summer learning practices. Program impacts from experimental evaluations were identified for outcomes ranging from math and reading achievement to an increased likelihood of employment. Drawing from a limited number of ten experimental evaluations, we found that reading achievement gains were achieved for a handful of programs, whereas math achievement was less often a program focus and impacts were less consistent. Few impacts were found on high school completion, college enrollment, and employment. Finally, a lack of evidence was found for youth development and health and fitness outcomes due to the fact that these outcomes were rarely, if ever, evaluated. Several recommendations for practice, research, and evaluation are presented. The literature reviewed, though limited, indicates that programs leading to academic improvement include the following characteristics: making learning fun, interactive, and hands-on, delivering academic content that complements curricular standards, hiring experienced and trained teachers, keeping class sizes small, and encouraging parents to teach children how to become better readers. For disadvantaged students, making programs affordable and accessible, involving parents, and involving the community appear to be aligned with best practices. A bibliography of summer learning and out-of-school time resources is provided. Five appendixes are included: (1) Tables 1-3; (2) Table 5; (3) Tables 6-7; (4) "Lessons from Youth Development Research and Evaluation" (Kristin Anderson Moore, April 2008); and (5) Past and Current Funding Sources. (Contains 12 tables and 48 endnotes.)