Social Impact Bonds, or Pay for Success (PFS) as known in the U.S., have attracted inordinate attention as a novel strategy for financing and providing preventative services to our most vulnerable populations. We undertake an exploratory, qualitative analysis of the Preschool PFS feasibility pilot grant applications and projects initiated by the U.S. Department of Education to encourage state and local exploration of PFS for implementing high-quality preschool programs. Drawing on the public administration evidence base that informs PFS design, we examine the feasibility pilot features and investigate why grant applicants saw PFS as a promising strategy for achieving their preschool program goals. We also uncover challenges encountered, lessons learned, and the perceived viability of fully executed PFS preschool programs. We find that few projects are advancing toward formal PFS arrangements, with many struggling to overcome constrained capacities, structural and political barriers, and inherent incentives to minimize risk and loss (author abstract)