Kwoh is active with foundations and other philanthropic organizations. He has been Chair of the Board of Directors of The California Endowment, which is the largest health foundation in California. He is one of the first Asian Americans to chair the board of a large foundation in the U.S. Kwoh has also been chair of the Methodist Urban Foundation, vice-chair of the California Wellness Foundation, and a trustee of the California Consumer Protection Foundation, The Tang Family Foundation, the Fannie Mae Foundation, and a former Leadership Council member of California Forward.
