Photo of Tom  Cullinan

Tom Cullinan



Vanderbilt University School of Law, J.D.

State University of New York at Albany, M.S. of Taxation

State University of New York at Geneseo, B.S. Accounting


Recognized by Chambers USA: Guide to Leading Business Lawyers in the category: Tax (2009-2018)

Recognized by The Legal 500 United States in the category: U.S. Taxes: Contentious (2016-2017)

Selected for inclusion in Georgia Super Lawyers (2012-2018)

Named a “Rising Star” by Georgia Super Lawyers (2007)

Bar Admissions


Court Admissions

United States Supreme Court

United States Court of Appeals for the Second, Fifth, Seventh, Eleventh, D.C., and Federal Circuits

United States Court of Federal Claims

Multiple United States District Courts

United States Tax Court


Tom Cullinan is a Shareholder in the Firm's Atlanta office. Tom joined the Firm from the IRS, where he served as the Counselor to the IRS Commissioner and then as the acting IRS Chief of Staff.  

While at the IRS, Tom was a member of the Commissioner’s core leadership team, and he advised the IRS Commissioner on the most critical issues facing the agency, including the IRS strategic plan and budget, staffing, internal operations, enforcement of tax laws and service to taxpayers. He was particularly involved in high-level enforcement issues.  Among other things, Tom either conceived or helped launch the Office of Fraud Enforcement, the Office of Promoter Investigations, and the Joint Strategic Emerging Issues Team, all of which should be key IRS enforcement tools in the coming years. Tom also helped implement various policies pertaining to cryptocurrencies and served as an invited IRS representative to several Financial Stability Oversight Council meetings regarding cryptocurrencies.

Before joining the IRS, Tom spent twenty years as a tax attorney representing taxpayers in tax controversy matters. He has represented hundreds of taxpayers, including low-income individuals in pro bono matters, high net-worth individuals, partnerships, trusts and estates, and corporations in IRS audits, administrative appeals, and litigation, on a wide variety of tax issues often with significant amounts at issue. Tom pursues every possible opportunity to resolve tax disputes and is adept at negotiating acceptable resolutions. Yet, litigation is sometimes inevitable and he has a notable track record in that regard. Notable public representations include:

American International Group, Inc. vs. United States – Tom was lead tax counsel in the insurance company’s dispute with the United States regarding its entitlement to foreign tax credits.

Klamath Strategic Investment Fund, LLC vs. United States – Tom represented the taxpayers in what is now one of the most cited cases arising out the last wave of so-called tax shelter litigation, where the courts held that the taxpayers were not subject to penalties and were entitled to deduct some of their fees and costs for entering into what the IRS called a “Son of Boss” transaction.

BASR Partnership vs. United States – Tom represented the taxpayers in the Court of Federal Claims and the Federal Circuit, where those courts disagreed with Tax Court precedent to hold that an advisor’s fraud was insufficient to hold open the statute of limitations for assessing tax and, for the first time ever, that a “TEFRA” partnership was entitled to a recovery of litigation cost from the United States pursuant to the qualified offer provisions.

Tom works in the Firm’s tax controversy practice where he draws on both his extensive background representing taxpayers and his deep knowledge of the IRS organization, operations, and procedures.

Professional Affiliations

  • Member, Internal Revenue Service Advisory Council (IRSAC) (2015-2017), and Chair of the Large Business & International (LB&I) Subcommittee (2016-2017)
  • Member, Court Procedure and Practice Committee, American Bar Association Section of Taxation (2002 – present), Former Chair, Tax Shelter Litigation Subcommittee
  • Member, Civil and Criminal Tax Penalties Committee, American Bar Association Section of Taxation (2003 – present), Former Chair, Civil Penalties Subcommittee.
  • Member, Administrative Practice Committee, American Bar Association Section of Taxation (2003 – present)
  • Fellow, American College of Tax Counsel (2014 – 2019, 2023-present)
  • Former Member, Board of Governors, Court of Federal Claims Bar Association (2008 – 2010)




Seminars & Presentations

  • IRS Update: Considerations for Tax Practitioners after the IRS Moratorium on Processing Employee Retention Credit Claims (September 2023) Chamberlain Hrdlicka Webinar
  • Litigating (and Resolving?) Syndicated Conservation Easement Cases (June 8-9, 2023)

    NYU School of Professional Studies, 15th Annual Tax Controversy Forum

  • Large Case Litigation (March 26-28, 2018)
    United States Tax Court
  • Section of Taxation Midyear Meeting (February 8-10, 2018)
    American Bar Association (ABA)
  • The New Partnership Audit Rules (December 5-8, 2017)
    American Bar Association (ABA)
  • Exploring the Limits of the Evolving Economic Substance and Business Purpose Doctrines and Related Ethics Issues (November 15-17, 2017)
    Practising Law Institute (PLI)
  • NYU 9th Annual Tax Controversy Forum  (June 15 - 16, 2017)
    NYU 9th Annual Tax Controversy Forum 
  • 2017 TEI Region II Tax Forum (June 5 - 6, 2017)
  • Navigating the TEFRA Repeal and the Newly Enacted Partnership Audit Procedures (February 17, 2017)
    North Atlanta Tax Council (NATC) 
  • ABA's 33rd Annual National Institute on Criminal Tax Fraud and Sixth Annual National Institute on Tax Controversy (December 7, 2016 - December 9, 2016)
  • TEI Annual Conference (October 16, 2016 - October 19, 2016)
    TEI Annual Conference
  • Coming Changes to IRS Audits of Partnerships (June 24, 2016)
    NYU SCPS 8th Annual Tax Controversy Forum
  • Tax Executives Institute (TEI) 66th Midyear Conference (March 13, 2016 - March 16, 2016)
  • Litigating the Accuracy Penalty (January 29, 2016)
    ABA Section of Taxation 2016 Midyear Meeting
  • Tax Enforcement in a Resource-Challenged World (December 9, 2015)
    Criminal Tax Fraud and the National Institute on Tax Controversy
  • Challenging Tax Penalties  (June 5, 2015)
    NYU - 7th Annual Tax Controversy Forum 
  • Summonses, Subpoenas, IDRs: What the Changing Landscape Really Means (December 12, 2014)
    ABA 31st Annual National Institute on Criminal Tax Fraud & Fourth Annual National Institute on Tax Controversy
  • Tax Court Procedures: Pretrial Practices (October 17, 2014)
    ALI-CLE Handling a Tax Controversy: Audit, Appeals, Litigation & Collections
  • What Every Accountant Should Know About Privileges and Work Product (August 20, 2014)
    2014 Sutherland Tax Education Series: Important Legal Issues for Accountants 
  • Dual Perspectives on Privilege: A Federal and State View of the Attorney-Client Privilege and Work Product Doctrine (July 30, 2014)
  • Defending Taxpayer Penalties - Audit, Appeals and Litigation Considerations (May 22, 2014)
    TEI 2014 IRS Audits & Appeals Seminar: Insights and Skills for Tax Controversy Success
  • Trial Skills and Strategies Workshop, Ask the Experts: Top Civil Tax Practice Tips and Representation Strategies (December 11-13, 2013)
    ABA 30th Annual National Institute on Criminal Tax Fraud and 3rd National Institute on Tax Controversy
  • Tax Court Decisions Briefing, Opinion and Decision, Tax Court Rule 155, and Supplemental Proceedings (October 17-18, 2013)
    ALI Handling a Tax Controversy: Audits, Appeals, Litigation, and Collections
  • Tax Court Procedures: Commencement of a Deficiency Proceeding (October 17-18, 2013)
    ALI Handling a Tax Controversy: Audit, Appeals, Litigation, and Collections
  • Adventures Into The Unknown: Handling Audits and Litigation Involving Partnerships and Other Pass-Through Entities (June 7, 2013)
    NYU 5th Annual Tax Controversy Forum
  • Noteworthy Developments in Federal Tax Controversy (April 30, 2013)
    Sutherland Tax Education Series X
  • Webcast: Global High Wealth Audits and IRS Audits of Partnerships (December 13, 2012)
    The Knowledge Congress
  • Hot Topics in IRS Exam, Appeals, and OPR – An Open Forum Discussion (December 5-7, 2012 )
    ABA 29th  Annual National Institute on Criminal Tax Fraud and First National Institute on Tax Controversy
  • IRS Audit Process, Procedures & Program (November 2, 2012)
    Insurance Tax Conference
  • Is the IRS Always Right? Judicial Deference to Treasury Regulations and Other IRS Positions (June 15, 2012)
    NYU Tax Controversy Forum
  • Fifty Years of Court Procedure and Practice (May 11, 2012)
    ABA Tax Section Meeting
  • Civil Penalties: The Current State of Affairs and the Need for Reform (December 1, 2011)
    28th Annual National Institute on Criminal Tax Fraud and First National Institute on Tax Controversy
  • Recent Developments - The Statute of Limitations, the Economic Substance Doctrine, Penalties, and UTP/CAP (November 30, 2011)
    Tax Education Series IX
  • Economic Substance Codification (August 31, 2011)
    TEI Forth Worth Chapter Lunch
  • Promoter and Material Advisor Litigation and Related Proceedings Meeting (January 20, 2011)
    ABA Tax Section
  • High Net Worth Individuals: Large Case Examination Procedures (December 9, 2010)
    Windham Brannon, P.C
  • Civil Tax Penalty Abatements – Fact or Fiction? (November 3, 2010)
    ABA Nationwide Teleconference
  • Uncertain Tax Positions: The IRS Response to Taxpayer Concerns (October 1, 2010)
    Tax Education Series and Subsequent Webinar
  • Civil Tax Penalty Abatements – Fact or Fiction? (September 23, 2010)
    American Bar Association Tax Section Meeting and Subsequent ABA Nationwide Teleconference
  • Updates on Current Issues in Federal Tax (September 21, 2010)
    Tax Executives Institute Atlanta Chapter Fall 2010 Meeting
  • Understanding and Protecting Privileges - From Soup to Nuts for Tax Attorneys (August 5, 2010)
    Continuing Legal Education Presentation
  • Section 7701(o) – The Newly Codified Economic Substance Doctrine (June 16, 2010)
    Sutherland Tax Education Series VIII



  • IRS Budget Increase: Early Activity Shows a Focus on the Employee Retention Credit, Malta Pension Plans, Monetized Installment Sales, and Other Emerging Issues for Tax Enforcement, Vol. 25, Issue 3 of Journal of Tax Practice & Procedure, Fall 2023

  • Employee Retention Credit: IRS Audit Activity – What to Know and How to Prepare, U.S. Chamber of Commerce, Washington DC, (October 19, 2023)

  • An Old 'New' Defense To IRS Penalties (June 1, 2018)
  • Anti-Inversion Rule Down, But Not Out, With Texas Ruling (October 17, 2017)
  • Novel Theory in Wyly Case Could Change SEC Disgorgement (October 20, 2014)
  • How to Handle IRS IDRs (February 24, 2014)
    142 Tax Notes 839
  • 2013’s Top 10 Tax Controversy Cases (February 5, 2014)
  • Into the Wilds of TEFRA: Supreme Court May Offer New Guidance on Penalty Jurisdiction in Woods (August-September 2013 Issue)
    Journal of Tax Practice and Procedure
  • Practice Notes: The Quality Examination Process (September-October 2012)
    The Tax Executive
  • Is the IRS Always Right? Judicial Deference to Treasury Regulations and Other IRS Positions (August-September 2012)
    Reprinted with permission from Journal of Tax Practice and Procedure
  • Practice Notes:  Post-Appeals Mediation (July-August 2012)
    The Tax Executive
  • Practice Notes: The Work Product Doctrine (May-June 2012)
    The Tax Executive
  • Economic Substance Doctrine: Unconstitutionally Vague? (February 7, 2011)
    130 Tax Notes 700
  • This One Left Us Jaded (January 21, 2008)
    118 Tax Notes 422