Susan Thompson Buffett Foundation (STBF)

STBF was the largest private funder of abortion access and abortion providers in the United States and the world as of 2024, having distributed over $8.4 billion in cumulative grants since its founding. As of 2023, it was reporting annual grantmaking of $695.2 million across 373 grants. Warren Buffett donated an additional $458 million in Berkshire Hathaway stock to the foundation in June 2025 as part of a $6 billion package of grants to five foundations, bringing his cumulative giving to the foundation and its predecessors to over $60 billion. ^{2 3 4 5}

The foundation was chaired as of 2024 by Warren Buffett’s daughter, Susan “Susie” Buffett, who should not be confused with the late Susan Thompson Buffett. The foundation’s president as of 2024 was Allen Greenberg, Susie Buffett’s ex-husband, whose compensation exceeded $800,000 in 2023. The foundation maintains a low profile, declining to publicize its abortion grantmaking and commonly appearing in grant acknowledgments only as “an anonymous donor.” ⁶

Background

The Susan Thompson Buffett Foundation was founded in 1964 by investor Warren Buffett, reportedly to address Buffett’s “Malthusian dread” of population growth among the global poor. Buffett and his longtime business partner Charlie Munger were also involved in other pro-abortion activities: Before the Roe v. Wade decision that mandated legal abortion throughout the United States, Buffett and Munger operated a nominal “church” that facilitated travel for pregnant women to places where abortions were available. ⁷

Through its early years, the STBF provided support for litigation seeking to overturn bans on the “partial-birth” late-term abortion procedure. The group funded lawsuits that successfully overturned a partial-birth abortion ban in Warren Buffett’s home state of Nebraska. ⁸ (A subsequent federal prohibition was upheld by the Supreme Court.)

The Foundation was originally secondary in Buffett-aligned giving, trailing the corporate giving of Buffett’s company, Berkshire Hathaway, which also supported pro-abortion and population control groups. That changed in the early 2000s after protests by pro-life groups brought controversy to Berkshire Hathaway’s business operations and Buffett’s semi-estranged first wife, Susan, died. ⁹

After Susan’s death, Warren Buffett stepped down from the Foundation’s board and his daughter Susie took over as board chair. Susan Buffett’s estate bequeathed the Foundation approximately $2.5 billion, and the Buffett Foundation was renamed in her honor. ¹⁰

In 2006, Warren announced that he would contribute most of his then-estimated $44 billion fortune ¹¹) to a number of philanthropic efforts. While the most prominent pledge went to the Bill and Melinda Gates Foundation, Buffett also made substantial pledges to four foundations controlled by his children: The NoVo Foundation, the Sherwood Foundation, the Howard G. Buffett Foundation, and the Susan Thompson Buffett Foundation. ⁹

Warren Buffett’s annual donations to STBF grew substantially beginning in 2024. In December 2024, Buffett donated $1.2 billion in Berkshire Hathaway stock to the family foundations, with the STBF receiving the largest single share. In June 2025, Buffett donated an additional $6 billion across five foundations, with STBF receiving approximately $458 million as 943,384 Class B shares, again the largest allocation among the family foundations. Buffett’s cumulative giving to the five foundations crossed $60 billion with the June 2025 donation. ^{12 13}

In 2024, Warren Buffett revised his estate plan significantly, announcing that upon his death, 99.5 percent of his remaining fortune, estimated at approximately $145 billion as of mid-2025, would flow into a new charitable trust to be administered by his three children (Susie, Howard, and Peter) who would be required to reach unanimous agreement on disbursements within ten years of his passing. Buffett additionally confirmed that the Bill and Melinda Gates Foundation would receive no further contributions after his death, a departure from his original 2006 pledge. Three independent trustees were subsequently added to the trust to provide succession in the event that any of his children could not continue in their roles. ^{14 13}

Funding

Between 2002 and 2018, Warren Buffett contributed $2.26 billion to the Buffett Foundation. Following her death in 2004, Susan Thompson Buffett’s estate contributed $2.9 billion to the foundation. ¹⁵

In 2020, the Susan Thompson Buffett Foundation was one of the key recipients of a $15.97 million gift of Berkshire Hathaway stock from Warren Buffett. ¹⁶

In November 2022, according to the Securities and Exchange Commission, the Susan Thompson Buffett Foundation received 1.5 million Class B shares in Berkshire Hathaway stock from Warren Buffett, part of $750 million in Hathaway stock that he donated that month to the Buffett Foundation as well as the foundations run by his children including the Sherwood Foundation, the Howard G. Buffett Foundation and the NoVo Foundation. ^{17 18}

Grants to Other Organizations

Between 2002 and 2020, the Susan Thompson Buffett Foundation paid out $7.6 billion in grants: ¹⁹