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Diana L. Erbsen

Diana L. Erbsen

Diana is a brilliant lawyer who can navigate complex tax issues.
Chambers USA 2023

Diana Erbsen has more than two decades of experience in tax controversy, representing clients in all aspects of sophisticated, challenging, and often high stakes tax disputes. In 2014, Diana was appointed to the position of Deputy Assistant Attorney General for Appellate and Review for the Tax Division of the US Department of Justice by President Obama. Following the end of the administration on January 20, 2017, Diana returned to DLA Piper as a partner.

In her capacity as a Presidential appointee to the DOJ's Tax Division, Diana oversaw its largest section, the Appellate Section (which is responsible for all appellate litigation, including to the Supreme Court), the Office of Review (which is responsible for civil settlements), and the Financial Litigation Unit (a unit tasked with collecting judgments secured by the Trial Sections of the Tax Division). Additionally, she was actively involved in the management and operations of the Civil and Criminal sections of the Tax Division and served in an ex officio capacity on the Bankruptcy Rules Advisory Committee. In January 2017, Diana was recognized by IRS Chief Counsel William Wilkins with the Chief Counsel Award for her leadership and oversight of the Appellate Section.

Since returning to DLA, Diana has resumed representing public and privately held corporations, as well as partnerships, estates and individuals, in all aspects of tax disputes. She concentrates her practice on federal, state and local tax controversies, including criminal tax matters. Informed by her experience at the DOJ and her historical perspective, she regularly counsels clients on issues relating to judicial deference to IRS guidance, including regulations, as well as on the appeal process and the intersection of criminal and civil tax enforcement.

In 2020, Diana served as Chair of the IRS Advisory Council (IRSAC), which advises the IRS Commissioner on tax administration issues.  In 2019, she served as Chair of IRSAC's Large Business & International Subgroup, after having been selected in 2018 to serve a three year term on IRSAC.  Diana's IRSAC service, along with her role in the leadership of the American Bar Association Tax Section, facilitates her ability to provide up to the minute guidance to clients and to help improve tax administration for the benefit of taxpayers and the IRS.

Diana has also been recognized by the American College of Tax Counsel as a Fellow.

Bar admissionsConnecticutDistrict of ColumbiaNew York
CourtsSupreme Court of the United StatesUnited States Tax CourtUnited States Court of Appeals for the Federal CircuitUnited States Court of Appeals for the Second CircuitUnited States Court of Federal ClaimsUnited States District Court for the Southern District of New YorkUnited States District Court for the Eastern District of New York


Among the specific, highly skilled areas in which Diana has had substantial experience are the following:

  • Representing clients in connection with subpoenas issued by the Senate Permanent Subcommittee on Investigations;
  • Representing clients in connection with art related matters (including estate and gift tax, auction house guarantees, sales tax and alleged fraudulent transfers);
  • Representing accounting firms and accountants in matters involving their ethical obligations (including pursuant to Circular 230) and their obligations under federal and state tax laws (including relating to material advisor rules, preparer penalties and disclosure of taxpayer information); and
  • Assisting individual and institutional clients in becoming compliant with US tax laws (including with regard to undisclosed foreign financial accounts and assets).
  • LL.M., New York University
  • J.D., Northeastern University
  • B.A., Amherst College, cum laude
    Charles Hamilton Houston Fellowship for Scholarship & Citizenship and John Woodruff Simpson Fellowship for the Study of Law


  • Chambers USA
    • Band 3, Nationwide Tax: Controversy (2021-2023) 
    • Band 4, Nationwide Tax: Controversy (2020) 
  • The Legal 500 United States
    • Recommended, US Taxes: Contentious (2018-2023)
      "I have been working with Ellis Reemer and Diana Erbsen. Ellis' lifetime experience in contentious tax matters is invaluable in terms of developing strategy. Diana Erbsen's service with the Internal Revenue Service has provided an invaluable insight into certain policy considerations and procedural action." – Client, The Legal 500 2023
  • Received the Chief Counsel Award for her leadership and oversight in the Appellate Section of the Tax Division for the U.S. Department of Justice by IRS Chief Counsel William Wilkins (January 2017)



  • Panelist, "Updates from the IRS Office and US Tax Court," 15th Annual Tax Controversy Forum, New York University School of Professional Studies, New York (June 2023)
  • Panelist, "Analyzing transfer pricing cases and controversy strategies," International Tax Review (ITR) Annual Women in Tax Forum, New York (March 2023)
  • Panelist, "What Every Tax Litigator Needs to Know About the Appeal of Their Civil or Criminal Tax Case," 2022 ABA 39th Annual National Institute on Criminal Tax Fraud & Tax Controversy, Las Vegas (December 2022)
  • Panelist, “Sensitive Audits: Ethical Considerations,” 2021 ABA 38th Annual National Institute on Criminal Tax Fraud and 11th Annual National Institute on Tax Controversy, Las Vegas (December 2021)
  • Chair, "Internal Revenue Service Advisory Council (IRSAC) Virtual Public Meeting," (November 2020). 2020 Annual Report available here
  • Panelist, "Docketed vs. Undocketed Appeals?  A look at the case from the perspective of IRS Counsel and Appeals," IRS Representation Conference, (November 2020)
  • Panelist, "Careers in Tax Law - Lunchtime Panel," American Bar Association, (July 2020)
  • Panelist, "Plenary: Voluntary Disclosures and Addressing the Sins of the Past: Ethical and Other Considerations" ABA National Institutes: Criminal Tax Fraud/Tax Controversy, Las Vegas, Nevada (December 2019)
  • Panelist, "Important Developments in Administrative Practice," ABA Tax Section, San Francisco (October 2019)
  • Panelist, "Preserving Your Challenges Under the Administrative Procedures Act: More Important Now Than Ever," NYU School of Professional Studies Tax Controversy Forum, New York (June 2019)
  • Panelist, "Standards of Tax Practice All New Two-Minute Drills," ABA Section of Taxation, New Orleans (January 2019)
  • Panelist, "Litigating Whistleblower Cases in the Tax Court," ABA Section of Taxation, Atlanta (October 2018)
  • Interviewer, with Nina E. Olson (National Taxpayer Advocate), "Tax Compliance and Enforcement Update Part II - IRS Taxpayer Advocate Update" 10th Annual NYU Tax Controversy Forum, New York (June 2018)
  • Panelist, "Implications of IRS Non-acquiescences," ABA Section of Taxation, Washington, DC (May 2018)
  • Moderator, "Managing Tax-Related Whistleblowers, Leaks and Derivative Suits," International Tax Enforcement and Controversy Conference, Washington, DC (October 2017)
  • Panelist, "Recent Practice Changes at IRS Appeals," ABA Section of Taxation, Austin (September 2017)
  • Panelist, "Plenary Session: Women, Leadership & Law," Northeastern University School of Law Women in the Law Conference, Boston (May 2017)
  • Panelist, "Presidential Transition in the Treasury Department and DOJ Tax," Federal Bar Association Tax Law Conference, Washington, DC (March 2017)
  • Panelist, "Careers in Tax Law," Federal Bar Association, Washington, DC (March 2017)
  • Panelist, "Civil Enforcement Priorities," ABA National Institute on Criminal Tax Fraud and Tax Controversy, Las Vegas, Nevada (December 2016)
  • Panelist, "Good News: Your Audit Is Over. Or Is It? The Process and Impact of a Joint Committee Review," ABA Section of Taxation, Boston (September 2016)
  • Panelist, "Current Developments, Court Practice & Procedure," ABA Section of Taxation, Boston (September 2016)
  • Speaker, with Deputy Solicitor General Malcolm Stewart, "Tax Appeals," IRS National Office CLE, Washington, DC (July 2016)
  • Panelist, "Tax Enforcement Updates," NYU Annual Tax Controversy Forum, New York (June 2016)
  • Speaker, Federal Bar Association's Women in Tax Law Luncheon Series, Washington, DC (June 2016)
  • Panelist, "Current Developments, Court Practice & Procedure," ABA Section of Taxation, Washington, DC (May 2016)
  • Speaker, "Current Civil and Criminal Enforcement Priorities," ABA Section of Taxation, Washington, DC (May 2016)
  • Panelist, "Current Developments, Court Practice & Procedure," ABA Section of Taxation, Los Angeles (January 2016)
  • Panelist, "Tax Careers in Government," ABA Section of Taxation, Los Angeles (January 2016)

Media Mentions

  • Quoted in, "Tax Court Amicus Rule Could Lend Heft To Pro Se Cases," Law360, September 7, 2023
  • Quoted in, "Federal Tax Cases To Watch In 2nd Half Of 2023," Law360, July 6, 2023
  • Quoted in, "Top Federal Tax Cases In 1st Half Of 2023," Law360, July 3, 2023
  • Quoted in, "Supreme Court Hands Victory To Tax Advisors—And Loss To IRS—In CIC Services Case," Forbes, May 17, 2021
  • Quoted in, "Rettig says pandemic gave IRS ‘momentum’ to overhaul taxpayer services," Federal News Network, November 25, 2020
  • Featured in, "IRS Advisory Council issues 2020 Annual Report," IRS, November 18, 2020
  • Quoted in, "IRS Makes Changes to Hot-Button Tax Capital Reporting Requirement," TaxNotes, October 23, 2020
  • Quoted in, "After Cranking Out $267 Billion in Stimulus Payments, IRS Faces Fresh Challenges," The Wall Street Journal, June 6, 2020: "It’s going to be a judgment call," said Diana Erbsen, a lawyer at DLA Piper in New York who is chairwoman of the agency’s advisory council. "It’s not going to be an on-off switch."
  • Quoted in,"Making the World Safe for Treasury Interpretations," TaxNotes, July 1, 2019
  • Quoted in, "Hints at Fate of Auer Deference Might Be Gleaned From Fax Case," TaxNotes, June 24, 2019
  • Quoted in, "E-Filing Penalties Case Takes Unconventional Turn," Tax Analysts, March 15, 2019
  • Quoted in, "Circuit Court Punts on Application of Boyle to E-Filing," January 31, 2019
  • Quoted in, "12 Books Tax Attorneys Should Read Before Summer Ends," Law360, August 17, 2018
  • Featured in, Northeastern University School of Law Magazine, August 2018
  • Quoted in, "Former Officials Back IRS for Not Accepting Court Decisions," Tax Analysts, May 15, 2018
  • Quoted in, "Case on Reasonable Cause for E-Filing Rejection Comes to a Head," Tax Analysts, February 2018
  • Featured in, "DLA Piper partner Diana Erbsen named to IRS Advisory Council" DLA Piper, January 16, 2018
  • Featured in, "IRS Appoints Seven New Members to Advisory Council," Daily Tax RealTime, Bloomberg, January 11, 2018
  • Quoted in, "IRS Appeals Moving Back to In-Person Conferences," Tax Notes, September 18, 2017
  • Quoted in, "Overcharging? The Implications of Marinello," Tax Notes, August 28, 2017
  • Featured in, "The Laterals Audit: Tax Attorney Moves In April," Law360, April 28, 2017
  • Featured in, "U.S. Claims Victory in Santander's $234 Million STARS Case," Bloomberg BNA, December 19, 2016
  • Featured in, "Journal of Tax Practice and Procedure, Message from the chair of the NYU Tax Controversy Forum," Wolters Kluwer, October 7, 2016
  • Featured in, "U.S. Argues Santander STARS Transaction Lacked Substance," Bloomberg Law, June 9, 2016
  • Quoted in, "Business Mgmt: Ignore new IRS notices at your peril," Bloomberg Law, February 22, 2016
  • Featured in, "CPAJ: Curbing tax evasion through offshore bank deposits in Swiss banks: a high priority for the Obama administration," Bloomberg Law, October 1, 2015
  • Quoted in, "BB&T Tax Shelter Was 'Simply a Money Machine,' Court Rules," Bloomberg Law, May 14, 2015
  • Featured in, "Appeals Court Dismisses Clergy Housing Lawsuit," Bloomberg Law, November 13, 2014

Prior Experience

  • Deputy Assistant Attorney General for Appellate and Review, Tax Division of the US Department of Justice
  • Attorney-Adviser, Hon. Robert Armen, Jr. US Tax Court