• M.S. (Accounting)
    New York University’s Leonard N. Stern School of Business
  • LL.M. (Taxation)
    New York University School of Law
  • J.D.
    New York University School of Law
  • B.A.
    Stanford University

James Warren represents utilities in all aspects of federal tax matters. These matters include operational and transactional tax advice and representation in tax controversies with the Internal Revenue Service (IRS) at the audit and appeals level, as well as in connection with applications to the IRS National Office for private letter rulings and technical advice. Mr. Warren also advises many clients on a variety of tax accounting issues. He has proven experience developing broad-based tax solutions for utility companies that reflect the critical tax, accounting and regulatory perspectives.

Mr. Warren has developed strategic analyses of the tax consequences of deregulation and restructuring for electric industry clients and has developed financial and regulatory options for minimizing the impact of taxes incurred during that process. In this regard, he has assisted clients in the structuring of fossil fuel and nuclear plant transfers (including decommissioning liabilities for the latter), the realignment of contractual relationships, the structural reconfiguration of businesses and many of the regulatory implications of these activities. In addition, he has assisted utility clients with their participation in alternative energy investments including designing programs intended to promote the development of solar generation in their service territories and in trying to achieve commercial parity with non-regulated competitors.

Mr. Warren has assisted utilities and their regulators in identifying and resolving tax normalization problems by obtaining guidance from the IRS National Office. He is experienced in contesting IRS coordinated utility and other issues on behalf of utility clients and has represented entire utility industry segments in connection with certain tax positions adopted or under consideration by the IRS.

Mr. Warren frequently serves as an expert tax witness in utility proceedings before the Federal Energy Regulatory Commission (FERC) and numerous state utility commissions. He has testified on legislative and administrative issues relative to the utility industry before several Congressional committees and subcommittees, and at Department of Treasury hearings.

Mr. Warren is a Certified Public Accountant. During his professional career, he has been a tax partner in several international accounting firms. He frequently speaks before utility, tax, finance and legal executives.

  • Addressing with the IRS National Office the issue of the assignment of the value of a plant-specific purchase power agreement to the related generating plant.
  • The procurement from the IRS National Office of multiple private letter rulings requiring the recognition of net operating losses in the establishment of utility rates.
  • Representation of the owners of nuclear generating plants before the IRS and Treasury in proposing modifications to the tax rules applicable to funding the decommissioning of those plants.
  • The procurement of multiple private letter rulings from the IRS National Office regarding the status of various types of electric generating facilities under the tax normalization rules. 
  • Chambers USA: Tax (District of Columbia), 2010 - 2015
  • International Tax Review: Tax Controversy Leaders (U.S.), 2015, 2017
  • Legal 500: Tax: Non-Contentious, 2013, 2015, 2018
  • Legal 500: Tax: Contentious, 2013
  • American Bar Association
  • District of Columbia Bar
  • Federal Bar Association
Bar Admissions
  • District of Columbia
  • New Jersey
  • New York
Speaking Engagement

James Warren and Alexander Zakupowky will be speaking at the Edison Electric Institute (EEI) and American Gas Association (AGA) Taxation Committee Meeting in Austin, Texas, on November 12, 2018.

Austin, TX

Speaking Engagement

George A. Hani and James I. Warren will present during the Energy Tax Council conference on September 18, 2018 in St. Augustine, FL.

St. Augustine, FL

Speaking Engagement

James I. Warren and Alexander Zakupowsky will present during Edison Electric Institute's (EEI) 2018 Taxation Committee Meeting on June 25, 2018.

Asheville, NC

Speaking Engagement

James I. Warren and Alexander Zakupowsky will present during the American Gas Association (AGA) Taxation Committee Meeting from June 3-6, 2018.

Park City, UT