(IOs) are influential policy actors in higher education. Yet, little is known regarding the role of philanthropic foundations in sponsoring IOs for policy promotion. By relying on longitudinal analysis of grants, semi-structured interviews, and social network analysis, this study examined the most central IOs within foundation-sponsored networks, documenting rationales behind this grantmaking strategy. Data included nearly 7,000 grants from 2004 to 2014, representing nearly $3b in postsecondary funding. Results demonstrated that over a decade, the field of higher education philanthropy has shifted, with a decrease in traditional forms of grantmaking and an increase in field-building efforts. Specifically, grants flowing to IOs focused on policy advocacy and completion purposes, or what can be described as a high-leverage approach to educational philanthropy. Furthermore, the most influential voices within philanthropic-sponsored networks were linked to the college completion agenda, a powerful reform movement seeking to increase national degree productivity. By emphasizing philanthropic organizations and their relationships with IOs, this study extends postsecondary policy analysis from a state-centric approach to one that considers non-state actors' role in policy advocacy and educational reform.