This report is the last in a series funded by The Wallace Foundation and developed by Public/Private Ventures (P/PV) and The Finance Project to document the costs of out-of-school-time (OST) programs and the city-level systems that support them. The report examines the development of OST systems in six cities across the country and summarizes the strategies and activities commonly pursued, their associated investments and options for financing such system-building efforts. These findings can provide OST stakeholders with critical information to help guide their investments in system planning, start-up and ongoing operations. The report serves as a companion to two previous resources: "The Cost of Quality Out-of-School-Time Programs," which provides information on both the average out-of-pocket expenditures and the average full cost of a wide range of quality OST programs; and an online cost calculator that enables users to generate tailored cost estimates for many different types of OST programs. Appendices include: (1) Catalog of System-Building Investments; (2) OST System-Building Profiles for Boston, Charlotte, Chicago, Denver, New York and Seattle; and (3) Endnotes. (Contains 9 tables, 17 figures, and 64 endnotes.) [For the synopsis of this report, see ED507375.]