" Federal, state, and local agencies play an important role in improving social outcomes for society's most vulnerable populations. A small number of state, local, and foreign governments are employing PFS to fund efforts designed to better serve these vulnerable populations. GAO was asked to provide information about PFS. This report examines (1) how selected PFS projects have been structured and what potential benefits these projects can provide; (2) how selected PFS contracts have been structured to address potential project risks; and (3) the potential roles for the federal government's involvement in PFS projects. To address these objectives, GAO reviewed relevant literature on PFS; selected 10 PFS projects that reflected a variety of policy areas and were in different stages of implementation in state and local governments in the United States and the United Kingdom, where PFS originated; reviewed key documents and interviewed stakeholders from organizations that played a role in the selected projects; and reviewed documents and interviewed officials from the eight federal agencies that participated in an informal PFS working group. "