Kat Saunders Gregor


  • JD, cum laude, Harvard Law School, 2005
  • BS (Accounting), magna cum laude, Georgetown University, 2000


  • England and Wales, Solicitor, 2009
  • New York, 2006
  • Massachusetts, 2006

Court Admissions

  • U.S. Court of Appeals for the Federal Circuit, 2008
  • U.S. Tax Court, 2008
  • U.S. Court of Federal Claims, 2006
  • Boston Business Journal 40 Under 40 (2016)
  • Massachusetts Super Lawyers Rising Star (2013-2016)

Kat Saunders Gregor


Kat is a tax partner and co-founder of the Tax Controversy Group. Kat regularly handles disputes with the IRS and other administrative bodies, and assists clients in managing disputes with non-U.S. tax authorities. Kat represents public companies, private investment funds, institutional investors, private companies and high net worth individuals before the IRS, U.S. Tax Court, U.S. Court of Federal Claims and other federal and state courts.

Kat’s practice encompasses a wide range of partnership and international tax issues, with a focus on the asset management and life sciences industries. Kat advises private investment fund managers on structuring and launching funds, and has worked extensively on fund investment and secondary transactions. She also represents public and private clients in ongoing tax issues, as well as merger, acquisition and restructuring transactions.

Kat previously practiced as a CPA with PricewaterhouseCoopers LLP, where she advised venture capital funds and their portfolio companies on tax compliance, planning, and controversy matters.


  • Representing a large hedge fund in ongoing proceedings in the U.S. Court of Federal Claims, the U.S. Tax Court and the Court of Appeals for the Federal Circuit.
  • Lead counsel representing a client before the U.S. Tax Court in a dispute regarding administrative due process.
  • Lead counsel representing a multinational energy company before the Massachusetts Appellate Tax Board, achieving a complete victory in a multi-million dollar dispute over local taxes.
  • Lead counsel for a charitable estate in a U.S. Tax Court dispute regarding the decedent’s taxable income, achieving a favorable resolution through a referral to the IRS Appeals Office.
  • Representing several pharmaceutical and medical device companies in IRS examinations following regulatory settlements with the FDA, DOJ and SEC.
  • Represented the U.S. subsidiary of a multi-national software company regarding an ongoing dispute with the IRS regarding intercompany transfer pricing arrangements.
  • Represented a film production company in an IRS appeal regarding significant personal holding company issues.
  • Represented a large U.S.-based software company in an IRS appeal regarding the deductibility of management fees paid to private equity sponsors; represented several portfolio companies in similar disputes at the IRS examinations level.
  • Represented numerous clients before the IRS, state and local revenue agencies, and non-U.S. tax administrative bodies.
  • Represent asset management clients in the formation of new funds and ongoing operational matters, including Pacific Equity Partners, Gauge Capital, Moelis Capital Partners, Bain Capital and GMO.
  • Advise various institutional investors in investments in private equity, hedge and other alternative assets investment funds.
  • Advised Altamont Capital in its acquisition of the specialty pharmacy divisions of Modern HEALTHcare.
  • Advised NSTAR, a gas and electricity company, in its merger with Northeast Utilities, which created one of the nation’s largest utilities (with a total enterprise value of $17.5 billion).
  • Represented an ad hoc committee of Second Priority Senior Secured Noteholders in the restructuring of Satelites Mexicanos S.A. de C.V. through a prepackaged chapter 11 plan, which was honored as “Deal of the Year 2011” by Latin Lawyer Magazine.
  • Advised Gridiron Capital in connection with the acquisition of Quality Solutions.
  • Advised multiple large private equity firms, hedge funds and strategic investors making investments in traditional, emerging and frontier markets.


  • Kat Gregor and Laura Hoey, “Tax Reform: Deductibility of Government Payments Materially Limited,” Westlaw Journals Securities Litigation & Regulation (January 25, 2018) 
  • Kat Gregor, Gabrielle Hirz and Isabelle Farrar, “How IRS Is Targeting Offshore Accounts, Virtual Currency,” Law360 (January 23, 2018)
  • Quoted, “'Willfulness' In Civil FBAR Cases Comes Down To The Facts,” Law360 (November 21, 2017)
  • Gabrielle Hirz, Kat Gregor and Stefan Herlitz, “Remaining Silent Before the Tax Man,” Bloomberg BNA's Daily Tax Report (September 26, 2017)
  • Kat Gregor, “Q&A: Resolving Tax Disputes with Regulators,” Corporate Disputes (July-September 2017)
  • Kat Gregor and Gabrielle Hirz, “Staying on Issue: The Internal Revenue Service’s New Issue-Based Audits,” Risk & Compliance (July-September 2017)
  •  Kat Gregor, Veronika Polakova and Kathryn Seevers, “One Step Closer: An Update on Partnership Audit Reform in the United States,” Risk & Compliance (April-June 2017)
  • Kat Gregor, Gabrielle Hirz and Hillel Nadler, “The IRS Needs Help,” Law360 (February 2, 2017)
  • Kat Gregor, “Q&A: Resolving tax disputes,” Financier Worldwide Business Resource Series: Litigation & Alternative Dispute Resolution (November 2016)
  • Quoted, “IRS Studying How Partnership Audit Rules May Affect Exempts,” Bloomberg BNA (October 26, 2016)
  • Kat Gregor and Nicholas Berg, “Piggy Backing and Double-Dipping: What Asset Managers Can Learn From the Life Sciences’ Experience with the SEC and the IRS,” Journal of Taxation and Regulation of Financial Institutions (Fall 2016)
  • Kat Gregor and Gabrielle Hirz, “A Loose Standard For IRS Summons Enforcement,” Law360 (August 16, 2016) (subscription required)
  • Kat Gregor and Brittany Cvetanovich, “IRS on the Horizon: Partnership Audit Reform in the United States,”Risk & Compliance (January-March 2016)
  • Kat Gregor, Loretta Richard and Brenda Coleman, “Shifting Sands: When Tax Planning Morphs Into Tax Avoidance,” Risk & Compliance (October-December 2015)


  • Panelist,  “Transfer Pricing Controversy,” New England Regional IFA Conference (November 2017) 
  • Panelist, “Export Forum – Resolving Tax Disputes with Regulators,” Corporate Disputes (July-September 2017)
  • Panelist, “The Private Investment Fund Tax Master Class: Impact of the New Partnership Audit Rules: Going Beyond the Mechanics,” Financial Research Associates (May 2016)
  • Panelist, “New IRS Partnership Audit Regulations: What Every Tax Adviser Needs to Know: Planning Tools to Prepare for Massive Changes Ahead,” Strafford Webinar (May 2016)
  • Panelist, “Tax Strategies for Limited Partner Investors in Private Investment Funds: Avoiding Tax Traps Through Side Letters and Other ‘Hidden’ Agreements,” Strafford Webinar (April 2016)
  • Panelist, “Tax Court 101: Everything You Wanted to Know About Litigating Tax Cases,” American Bar Association, Tax Section Midyear Meeting (2016)
  • Panelist, “Tax Opinions, Privilege and Waiver,” International Fiscal Association, New England Branch Conference (2015)
  • Panelist, “IRS Audit Guide: What to Expect if/when the IRS Pays a Visit,” 17th Annual Effective Hedge Fund Tax Practices, Financial Research Associates (November 2015)
  • Panelist, “Tax Disputes in the US,” Corporate Disputes (2014)