Mary McNulty is a tax attorney in Holland & Knight's Dallas office. Ms. McNulty represents large business taxpayers in Internal Revenue Service (IRS) audits, appeals and tax litigation, with emphasis on federal tax procedural issues, interest, penalties and partnership audits. She has significant knowledge and experience in partnership tax issues relating to private equity, energy, real estate, and exempt organizations.

Industry sources say:

"She is a smart, dedicated and relentless lawyer - she won't stop until she figures the situation out."
"Mary has a wealth of tax experience that has been invaluable in helping us manage our complicated tax controversy issues."

Chambers USA – America's Leading Lawyers for Business 2024 guide

Ms. McNulty was listed as a "Leading Lawyer" in The Legal 500 USA guide from 2020 to 2022 and has been listed as a recommended attorney from 2015 to 2022. She was named the 2021 Outstanding Texas Tax Lawyer by the State Bar of Texas.

Representative Experience

  • Represents large business taxpayers in IRS audits and appeals involving oil and gas and energy tax issues, partnership tax issues as well as tax litigation and procedural issues, including statutes of limitations, penalties and interest
  • Represents a multinational company in an IRS audit and competent authority proceeding involving transfer pricing issues
  • Represents a tax matters partner in an IRS audit of partnership involving a novel self-employment tax issue
  • Successfully represents large corporations in the U.S. Court of Federal Claims and IRS administrative proceedings involving multimillion-dollar interest claims on federal tax deficiencies and refunds
  • Successfully represents families in IRS appeals and litigation in estate and gift tax valuation cases
  • Represents taxpayers in Freedom of Information Act (FOIA) requests, appeals, mediation and lawsuits
  • Served as special tax counsel in connection with the largest nonfinancial bankruptcy in U.S. history, with multibillion-dollar tax issues relating to the bankruptcy restructuring and IRS proposed tax adjustments
  • Prevailed in the U.S. Tax Court on a multimillion-dollar administrative adjustment request for a partnership refund, which involved complex partnership litigation procedural issues
  • Prevailed in the U.S. Tax Court in a case involving determination of the transfer price of Saudi Arabian crude oil, in which the alleged deficiencies totaled billions of dollars; the U.S. Court of Appeals for the Fifth Circuit affirmed, and the U.S. Supreme Court declined to hear the case on appeal
  • Prevailed in the U.S. Court of Appeals for the Federal Circuit in a case involving the deductibility of payments made to the Agent Orange settlement fund
  • Successfully litigated and defended in federal district courts privilege claims in motions to quash IRS third-party summonses
  • Prevailed in an IRS examination of a public manufacturing company's acquisition of foreign and domestic assets, partnership interests and stock
  • Prevailed in a multimillion-dollar offshore voluntary disclosure case
  • Represents private foundations, pension plans and other tax-exempt organizations making oil and gas renewable energy, real estate and other partnership investments


  • Southern Methodist University Dedman School of Law, J.D., cum laude
  • University of Notre Dame, B.B.A., with highest honors
Bar Admissions/Licenses
  • Texas
Court Admissions
  • U.S. Court of Appeals for the Federal Circuit
  • U.S. Court of Appeals for the Fifth Circuit
  • U.S. Court of Appeals for the Tenth Circuit
  • U.S. Court of Federal Claims
  • U.S. District Court for the Northern District of Texas
  • U.S. Supreme Court
  • U.S. Tax Court
  • Law360 Editorial Board Member, Tax Authority Federal, 2014-2024
  • American Bar Association, Section of Taxation, Vice Chair, Committee Operations 2022-2024; Council, 2012-2018; Appointments to the Tax Court Committee, Chair, 2015-2017, Vice Chair, 2013-2015, Member, 2007-2019; Nominating Committee, 2007-2010 and 2021-2024; Committee on Government Submissions, 2007-2015; Court Procedure and Practice Committee, Chair and Vice Chair, 2001-2007; Advisory Panel, 2006-2011
  • State Bar of Texas, Tax Section, Chair, 2011-2012; Vice Chair, 2010-2011; Secretary, 2009-2010; Treasurer, 2008-2009; Council, 2005-2008; Nominating Committee, 2013-2016, 2019; Committee on Government Submissions, Chair, 2007-2008; Energy Tax Committee, Chair, 2003-2005
  • Dallas Bar Association, Tax Section, Chair, 2005-2006; Vice President, 2004-2005; Secretary and Treasurer, 2003-2004; Council, 2002-2003
  • American College of Tax Counsel, Board of Regents, 5th Circuit Regent, 2021-2023
  • U.S. Tax Court Judicial Conference, 2001, 2003, 2007, 2009, 2015, 2018
  • The Family Place, Board Member, 2017-2021
  • Business Council for the Arts, Board Member, 2014-2023; Executive Committee, Secretary, 2018-2023; Executive Committee, Member, 2014-2017; Membership Committee, Chair, 2014-2017
  • Booker T. Washington High School for the Performing and Visual Arts, Advisory Board, 2011-2014; Executive Committee, 2012-2014; Finance Committee, Chair, 2013 -2014
  • Holland & Knight, Directors Committee, 2021-2024
  • Thompson & Knight, Management Committee, 2008-2012, 2019-2021
  • Thompson & Knight, Finance Committee, Chair, 2013-2016
  • Thompson & Knight, Legal Personnel Committee, Chair, 2005-2008
  • Christ the King Parents' Association, Executive Board, Treasurer, 2004-2005
  • American Cancer Society Evergreen Gala, Treasurer, 1993-1995
  • Current Developments, Business Entities, Board of Advisors and Department Head, 1999-2015
  • Journal of S Corporation Taxation, "Limited Liability Companies," Board of Advisors and Contributors, 1995-1998
Honors & Awards
  • The Best Lawyers in America guide, Litigation and Controversy - Tax; Tax Law, 2006-2024
  • The Legal 500 USA, Leading Lawyer, Tax – U.S. Taxes: Contentious, 2018-2023; Hall of Fame, Tax – U.S. Taxes: Contentious, 2024; Recognized Attorney, Tax: Domestic Tax; Tax: Tax Controversy, Tax: U.S. Taxes: Contentious, 2015-2022; Tax: International Tax, 2024
  • Chambers USA – America's Leading Business Lawyers guide, Tax: Controversy; Tax: Litigation, 2009-2024
  • Best Lawyers in Dallas, D Magazine, Tax: Litigation, 2007-2008, 2011-2015, 2017-2019, 2021-2024
  • Texas Super Lawyers magazine, Tax, 2003-2023
  • Dallas 500, Most Influential Leaders in North Texas, D CEO, Law: Tax, 2021
  • Outstanding Texas Tax Lawyer, State Bar of Texas, Tax Section, 2021
  • Top 50 Female Attorneys in Texas, Texas Super Lawyers magazine, 2014-2016, 2018
  • Top 100 Dallas/Fort Worth Region, Texas Super Lawyers magazine, 2014-2016
  • Top 100 Overall, Texas Super Lawyers magazine, 2016
  • The Best Lawyers in America guide, Dallas Lawyer of Year, Litigation and Controversy – Tax, 2014, 2016
  • Best Business Lawyers in Dallas, D Magazine, Tax, 2009
  • The Best Lawyers in Dallas Under 40, D Magazine, 2002
  • American Bar Foundation, Fellow
  • Texas Bar Foundation, Fellow
  • Thompson & Knight LLP Dallas Office Mentoring Award, 2002
  • Martindale-Hubbell AV Preeminent Peer Review Rated


Speaking Engagements