In 2009, under a grant from the Employment and Training Administration, the Nelson A. Rockefeller Institute of Government undertook a field network research study of selected sites to examine how Temporary Assistance for Needy Families (TANF) clients are served by the Workforce Investment Act’s (WIA) One-Stop Career Centers. The research sought to define the nature of the cooperative, administrative, operational and financial relationships between the WIA and TANF programs. The field research resulted in this report which contains a set of structured case studies of such relationships in Sacramento and Modesto Counties in California; Macon and Columbus Counties in Georgia; and the City of St. Louis and St. Louis County in Missouri. To inform this report, Rockefeller gathered and analyzed information on the experiences of key stakeholders in settings with a successful track record of serving TANF and other low-income populations through One-Stop Career Centers, where such experience is the result of local decisions rather than centralized state services or state-mandated program alignments. Rockefeller conducted interviews and on-site observations with key informants, including senior administrative and program management at the selected One-Stop Career Centers and the local Workforce Investment Board (WIB), as well as contacts with the employment and social service agencies at the state and county levels. The study also included an analysis of administrative data on client caseloads, types of services, and performance indicators.