Private foundations in the United States are powerful actors in contemporary society. Their influence stems in part from their lack of accountability – they operate free from market pressures or finding sources of funding, and they are not subject to formal democratic systems of checks and balances such as elections or mandatory community oversight. In recent decades, foundations have become increasingly influential in shaping public policy governing core social services. In US education policy, for example, the influence of private foundations has reached an unprecedented scope and scale. Although economic and electoral accountability mechanisms are absent, foundations are aware that their elite status is rooted in a wider acceptance of their image as promoters of the public good. They are incentivized to maintain their role as “white hat” actors and, in balancing their policy goals with the desire to avoid social sanctions, the ways in which they exert influence are shaped and limited by institutional processes. Drawing on rare elite interview data and archival analyses from five leading education funders, we observe that foundations seek to sustain their credibility by complying with legal regulations and by drawing on cultural norms of participation and science to legitimize their policy activities.