In recent years, there has been increased policy interest in the way young people spend their time out of school, and in promoting the availability of opportunities for them to spend this time in productive and developmentally supportive ways. Out-of-school opportunities (such as arts and music programs, sports teams, community service, youth entrepreneurship opportunities, and a broad range of after-school programs) are increasingly seen as potentially powerful tools to promote positive youth development and to prevent problematic behaviors and poor youth outcomes. In order to inform policy and practice that seeks to support youth development through the systems that affect young people and the programs available to them, it is essential to understand the nature of these opportunities, who participates in them, the reasons behind such participation, and the barriers and potential incentives that condition participation. This paper explores young people's perspectives on their out-of-school time and the influences, barriers, contexts, and processes that contribute to their choices and experiences. Research Questions guiding this study include: (1) How do young people find out about and initially decide to become engaged in structured activities? (2) What are the influences of key individuals in their lives, including parents, peers, and other adults? (3) What are the influences of their neighborhood and school contexts on these decisions? (4) What are the influences of program quality or content? (5) How important are the auspices under which activities are provided? (6) What barriers exist to program participation, and how do young people work to overcome these barriers? (7) What gaps exist between young people's interests and program availability? (8) What do young people expect to get out of programs, and how is this connected to their goals and expectations for the future? This study helps researchers and policymakers understand more about how youth negotiate both opportunities and constraints, the preferences they have, and what this suggests for policymaking and practice. In particular, it provides some insight into how to improve strategies for outreach, access, engagement, and provision. (Contains 4 figures and 1 table.)