Mary Duffy

Mary Duffy

Managing Director

Mary Duffy is a managing director and Head of Andersen’s US National Tax practice. She is also a member of Andersen’s U.S. Board of Directors.

Mary advises clients on tax policy, legislative and regulatory changes, accounting methods, accounting issues arising in transactions, and the tax implications of private aircraft. Mary is a frequent speaker for the Tax Executive Institute, the Practicing Law Institute, and other events.

Mary has extensive experience practicing before IRS National Office, handling accounting method change and ruling requests, as well as handling issues in an IRS examination. Mary works with individuals and businesses of all sizes and structures and has experience in many industries, including retail, manufacturing, energy, sports, entertainment, health, pharmaceuticals, and technology.

Immediately prior to joining Andersen, Mary served as one of two Legislation Tax Accountants with the Joint Committee on Taxation (JCT) from 2011 to 2013. While with the JCT, Mary worked with key tax personnel within Congress on the development and drafting of tax legislation and tax reform proposals. She also assisted in the review of large taxpayer refund claims submitted by the Internal Revenue Service for JCT review.

Prior to her work with the JCT, Mary was part of Deloitte's National Federal Tax Solutions tax practice, where she specialized in tax methods of accounting. Mary began her career in tax at Arthur Andersen in Chicago.