Current Horace Dutton Taft Alumni Medal Recipient

Paul H. Klingenstein ’74

2026 Horace Dutton Taft Alumni Medal Honoree

In recognition of a life and career defined by purpose, service, and dedication to Taft, Paul H. Klingenstein ’74 will be honored with the 2026 Horace Dutton Taft Alumni Medal. The medal is given each year to a person whose life’s work best reflects the essence of the Taft School motto: Non ut sibi ministretur sed ut ministret; Not to be served but to serve.

“In my eight years of service on the Horace Dutton Taft Alumni Medal Committee, I am not sure any candidate has embodied the Taft motto more fully than Paul Klingenstein,” noted Chair Laura Black Holt ’85, P’16,’18. “Not only has he expressed this through his decades-long commitment to our school, but also through his deep commitment to a long list of other educational, environmental, and health-related institutions, foundations, and organizations.”

After graduating from Taft in 1974, Klingenstein attended Harvard College, where he earned his bachelor’s degree. During and after his undergraduate years, he spent extended time in East Africa, an experience that proved formative. He worked as a field biologist with Dr. Iain Douglas-Hamilton at an elephant research site in Tanzania’s Lake Manyara National Park and later participated in large-mammal aerial surveys in Tanzania and Uganda. He also served as an Outward Bound instructor on Mount Kilimanjaro. These early years fostered a lasting interest in conservation, community, and the intersection of people and the natural world.

Klingenstein began his investment career at Warburg Pincus in the early 1980s, where he was involved in an early wave of biotechnology and managed care investing. He went on to earn his MBA from the Stanford Graduate School of Business in 1986 and soon after joined Accel Partners, then a newly formed venture capital firm. At Accel, he led a highly successful healthcare investing effort, working with a range of innovative companies in biotechnology, medical technology, and health-care services.

In 1999, Klingenstein founded Aberdare Ventures, a venture capital firm focused on health-care technologies. Over more than two decades, Aberdare became an active investor in areas ranging from drug discovery and development to highly engineered medical devices, personalized medicine, and data-driven health technologies.

Alongside his investment career, Klingenstein has been deeply engaged in philanthropy and global health. As an advisor to the Rockefeller Foundation, he helped launch the International AIDS Vaccine Initiative, an early public-private partnership dedicated to developing an effective HIV vaccine; he later served as a board member and chair. He has served on the board of the John D. and Catherine T. MacArthur Foundation and as vice chair of the Nia Tero Foundation, supporting Indigenous peoples and their stewardship of ancestral lands. He currently serves as a founding board member of the Global Health Investment Corporation and as board chair of the Campaign Legal Center, a nonpartisan organization dedicated to protecting democracy and the rule of law. His board service has also included the London School of Hygiene & Tropical Medicine, Juma Ventures, and Marin Country Day School.

Klingenstein’s commitment to Taft has been equally enduring. A former trustee, he has served on numerous school committees, including Admissions, Finance, Investment, School Life, and the Leadership Dinner Committee. He also continues a proud family legacy at Taft; his father, Lee P. Klingenstein ’44, received the Horace Dutton Taft Alumni Medal in 1998.

In 2014, Paul and his wife, Kathleen Bole, purchased Darwin Ranch, a remote guest ranch in Wyoming’s Gros Ventre River valley, supported by their nearby working cattle ranch, Ishawooa Mesa Ranch. Through their work there, Klingenstein has developed relationships on the Wind River Indian Reservation, including involvement in the reintroduction of buffalo. He and Kathleen have three adult children and four grandchildren and make their home in Wyoming.

“Paul’s history with Taft isn’t just measured in years, but in generations,” said Head of School Peter Becker ’95. “He has given so much of himself to this school—as a trustee, a mentor, and a friend—always driven by a genuine belief in Taft’s humanistic model of education. His remarkable record of leadership and service, both at Taft and beyond, embodies the spirit of the Horace Dutton Taft Alumni Medal.”

The Horace Dutton Taft Alumni Medal will be presented to Klingenstein at the Old Guard Dinner on Friday, May 8, 2026, at 6:30 p.m.

The Horace Dutton Taft Alumni Medal is the school’s highest alumni honor and is given each year to a person whose life work best typifies the school motto: Not to be served but to serve. The Horace Dutton Taft Alumni Medal is a reminder of Taft’s commitment to serve others.

For more info on the Horace Dutton Taft Medal, click here.