Mary Duffy

Mary Duffy is a Managing Director in Andersen’s US National Tax office and is the co-leader of Andersen’s accounting methods team. Mary also advises clients on tax policy and legislative matters and is a frequent speaker for Tax Executive Institute, BNA seminars, Andersen’s Family Office Roundtables and other events. 

Mary’s experience includes advising clients on complex tax accounting methods issues. Mary has years of experience practicing before IRS National Office handling accounting method change and ruling requests. Mary works with businesses of all sizes and structures, including managing accounting methods implementation projects, advising on issues arising in IRS examinations, and consulting on the financial statement implications of such issues under Accounting Standards Codification 740.

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 as well as various tax reform proposals. Mary also assisted in the review of large taxpayer refund claims submitted by the Internal Revenue Service for JCT review.

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