Prior to joining Barnes & Thornburg, Sean served as a partner at an Am Law 200 firm where he represented clients on a broad range of domestic and international tax matters. His practice routinely included representing partnerships in controversies arising from tax audits and adjustments as to the validity and allocation of items of income, deductions, and loss, including special allocations. Sean’s practice further included analyzing whether U.S. trade or business activities gave rise to effectively connected income (ECI), structuring inbound and outbound investments, and advising on withholding and reporting obligations. Additionally, Sean regularly counseled clients on employment tax compliance and worker classification issues.

Before practicing at law firms, Sean served as a member of the management group of the tax controversy practice for a Big Four accounting firm, where he assisted clients with their IRS and state tax controversies. This included advising on examination and collection matters, analyzing technical issues, addressing compliance considerations arising from extraordinary filing requirements, and providing representation during IRS and state administrative appeals. He routinely advised Fortune 500 companies, large fund-of-funds structures, and closely held businesses across a wide range of matters, including transfer pricing, intangible asset valuation, research credits, debt-equity determinations, and loss deductions.

Previously, Sean served as a Special Trial Attorney with the IRS Office of Chief Counsel, where he was responsible for issuing written guidance to IRS revenue agents, appeals officers, and settlement officers on substantive tax issues, as well as advancing and litigating some of the most important, sensitive, and complex tax cases for the Commissioner. His government experience provides valuable insight into IRS processes and enforcement priorities.