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

  • Federal Bar Association, 2024 Tax Law Conference, [Enforcement Criminal] Defending Malta Pension Plans – Lessons Learned and What Lays Ahead.., March 1, 2024
  • The University of San Diego School of Law & Chamberlain International Tax Institute, Tax Treaty Interpretation: Do They Mean What They Say (e.g Malta Pension Plans), February 20, 2024
  • Tax Controversy ERC Update: Pending Legislation, IRS Voluntary Disclosure Program, and Audit & Appeals Issues , Chamberlain Hrdlicka Webinar, Presented January 4th and 25, 2024
  • USC Gould School of Law 2024 Tax Institute, Handling High Wealth Tax Payer Examinations – What We Can Expect After the New IRS Inflation Reduction Act Funding, January 23, 2024
  • 71st Annual Taxation Conference – IRS Operations: Looking Back and Looking Ahead, University of Texas, Austin, Texas, December 14, 2023
  • 40th ABA Criminal Tax Fraud & Tax Controversy, Las Vegas, Keynote Panelist – A Look into the Future of IRS Enforcement – A Discussion with Leading Tax Controversy Thought Leaders, December 7-9, 2023
  • The Tax Man Cometh - What Increased IRS Enforcement Means for Taxpayers and Their Advisors, Chamberlain Hrdlicka 38th Annual Atlanta Tax and Business Planning Seminar, November 29, 2023
  • Keynote Lunch Discussion: A Peek Behind the IRS Curtain, and the Future of IRS Enforcement, Chamberlain Hrdlicka 46th Annual Houston Tax and Business Planning Seminar, November 1, 2023
  • 58th Annual Southern Federal Tax Institute, Tax Implications of Conservation Easement Donations: Recent Developments, November 1, 2023
  • Employee Retention Credit: IRS Audit Activity – What to Know and How to Prepare, U.S. Chamber of Commerce, Washington DC, October 19, 2023
  • 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



  • 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