He has also served at the Treasury's Office of International Tax Counsel (ITC); in the IRS' former Office of Senior Counsel, where his work focused on the identification of, and development of challenges to, certain abusive "listed" transactions; and with the Joint International Tax Shelter Information Centre (JITSIC), where he helped identify and develop challenges to a variety of cross-border abusive tax structures, including foreign tax credit generators. Prior to joining the IRS, he was associated with law firms in Boston, Miami, and New York.