William Foster

Incoming Managing Partner

William Foster is a partner in Bridgespan’s Boston office and the firm’s incoming managing partner. He was formerly the head of the organization’s US Advisory unit, and is an active thought leader on issues of philanthropy and social change.

Since joining the firm in 2002, William has supported the success of some of the sector’s most innovative philanthropies (e.g., Blue Meridian Partners, Co-Impact, TED) and some of the highest impact nonprofits (e.g., Youth Villages and Anti-Defamation League). He has a particular focus on the diligence, structuring, and supports required for philanthropic “Big Bets” and strong funding models for nonprofits. William has helped his foundation clients and a number of individual donors to craft some of the largest gifts in the sector.

Based on his clients’ experiences, William has dedicated himself to research on the topics of philanthropic "Big Bets" and nonprofit funding models. In February of 2019, the Stanford Social Innovation Review published “Becoming Big Bettable.” At the end of 2016, William collaborated with Forbes to publish its first ever list of “Big Bets for Social Change.” Additionally, in November of 2015, the Stanford Social Innovation Review published “Making Big Bets for Social Change.”

Among his other publications are: “When You’ve Made Enough to Make a Difference” (Harvard Business Review, 2011), “Ten Nonprofit Funding Models” (Stanford Social Innovation Review, 2009), “How Nonprofits Get Really Big” (Stanford Social Innovation Review, 2007), and “Should Nonprofits Seek Profits?” (Harvard Business Review, 2005).

William has served as the executive director of the Jacobson Family Foundation (now known as One8), an outcomes-oriented funder making grants to support educational excellence, equality, and Jewish continuity in the United States and Israel.

Prior to joining Bridgespan, William worked at Bain & Co. He received his BA from Harvard College and his MBA from Stanford University where he was an Arjay Miller Scholar. William is active in the Jewish community, serving on the board of Gann Academy.  He lives outside of Boston with his wife Rachel and their four wonderful children.



Big Bets 

Skoll World Forum

04/11/2018 | 60:00

Big Bets 

TedX Beacon Street

11/25/2015 | 15:32

Big Bets 

The Bridgespan Group

12/02/2015 | 0:64