Bob Stack is a managing director in Deloitte’s Washington National Tax practice. He advises U.S. companies on a full range of international tax issues and collaborates with Deloitte’s global member firms on international tax developments and initiatives, including those from the Organization for Economic Co-Operation and Development (OECD).

Bob joined Deloitte Tax from the U.S. Treasury Department, where he was the deputy assistant secretary for international tax affairs in the Office of Tax Policy from 2013 until 2017. He also was the official representative of the Obama administration for international tax policy and represented the US government at the OECD where he was involved in all aspects of the Base Erosion and Profit Shifting initiative. Prior to joining Treasury, Bob had more than 25 years of experience in international tax matters, representing both corporations and individuals.