Every application of Pay for Success (PFS) financing (e.g., recidivism, health care utilization, special education) must meet clear, measurable goals to obtain “payout” funding. Much of this journal focuses on how to structure contracts to achieve these goals. But larger questions remain. What is the ethical framework for choosing specific goals or setting programmatic priorities? How is one metric of success chosen over others? Insofar as the PFS interventions considered in this issue are presumed to be meeting societal goals, it is necessary to prioritize projects according to the priorities of society.