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 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. 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 2018, Diana was appointed to a three year term as a member of the IRS Advisory Council (IRSAC), which advises the IRS Commissioner on tax administration issues. She served as Chair of IRSAC's Large Business & International Subgroup in 2019 and has been selected as IRSAC's 2020 Chair. 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.