After Johns Hopkins, Garten worked in the Nixon, Ford and Carter administrations in a variety of foreign policy and economic positions. He then went on to Wall Street, becoming a managing director of Lehman Brothers and the Blackstone Group. At Lehman, he specialized in sovereign debt restructuring in Latin America. He also lived in Tokyo and directed and expanded the Asian investment banking business for that firm, including overseeing some of the largest international corporate restructurings of the era. At Blackstone he worked in the financial advisory and mergers and acquisitions arena. He then became the Undersecretary of Commerce for International Trade in the Clinton administration where he focused his efforts on trade and investment deals in "Big Emerging Markets" such as China, India, Indonesia, Brazil, Mexico, and Turkey. From 1996 to 2005, Garten was dean of the Yale School of Management after which he stayed on to teach full-time. His courses have included "Leading A Global Company", "Wall Street and Washington", "Managing Global Catastrophes", and "The Future of Global Finance", and he has led study trips for students to China, Singapore, Dubai, and London.