Ken “specializes in international tax of the utmost complexity."
Legal 500


Kenneth Klein concentrates his practice on international taxation, tax planning, tax transactions, tax controversies, and public policy. His tax practice experience has included planning, structuring/restructuring, mergers and acquisitions, other transactions, regulations, legislation, private letter rulings, examinations, administrative appeals, and amicus briefs. He has represented domestic and international clients in numerous industries, including manufacturing, transportation, financial institutions, software, pharmaceuticals, services, real estate, agricultural, trading, and entertainment, among others.

Ken has experience with outbound investments, inbound investments, structuring/restructuring, joint ventures, income bifurcation and amalgamation, controlled foreign corporations (subpart F), investments in US property, offshore intangibles, manufacturing, contract manufacturing, transportation (especially shipping), active royalties and rentals, software, other high tech, services, trading, insurance, source of income, foreign tax credits, and interest and other expense allocation and apportionment. His financial institutions experience extends to cross-border financings, portfolio interest, conduit financing arrangements, withholding tax, tax treaties, investment funds (stock, securities, commodities, venture capital, real estate and shipping), swaps, other derivatives, CDOs, other structured finance vehicles, catastrophe bonds, US and foreign stock and securities lending, foreign tax credit, controlled foreign corporations, source of income, and transfer pricing. He also has experience with the taxation of artists and athletes and international individual tax planning.

Prior to working at Mayer Brown, Ken worked at the IRS, first as Assistant Branch Chief and Attorney, Legislation & Regulations Division and General Litigation Division (1977-1981), and later as the Associate Chief Counsel (Technical) (1988-1990). Ken was an associate and then a tax partner at Cadwalader, Wickersham & Taft from 1981-1988 and 1990-2002. He also was Fellow of the American Society of International Law (1976-1977).

Ken is recognized year after year for his skills in international taxation. He has been lauded by clients for his "sophisticated cross-border tax planning, structuring and restructuring for a number of US and non-US multinationals." Legal 500 2015 refers to Ken as the ‘font of practical advice’ and has named him a leading lawyer for seven consecutive years. For the past nine years, Ken has been named to the World’s Leading Tax Advisers (Euromoney/International Tax Review). He is recognized as a leading tax controversy adviser in the International Tax Review Tax Controversy Leaders guide and named among the "Best Tax Lawyers" in Washington DC by Washingtonian Magazine and Washington Post Magazine. Ken has also been featured as a leading tax lawyer in Washington DC by Super Lawyers for nine consecutive years. Mayer Brown's Tax practice is ranked Tier 1 by Chambers USA, Legal 500 and the International Tax Review. Mayer Brown was also named Tax Practice Group of the Year by Law360 in 2015 and 2017.

Ken has been a speaker at numerous tax seminars.


  • 英语


The University of Georgia School of Law, 法律博士, 优等成绩
Articles Editor, Georgia Journal of International & Comparative Law

美国乔治敦大学法律中心, Masters of Laws in Taxation

University of Delaware, BA, magna cum laude


  • 华盛顿哥伦比亚特区


  • 美国最高法院
  • US Court of Appeals for the Fourth Circuit
  • US Tax Court
  • 美国哥伦比亚特区地方法院
  • US Court of Federal Claims


  • Board of Trustees, Legal Aid Society of the District of Columbia, 2009–; Vice President, 2014-2016; President, 2016-2018 
  • Board of Visitors, University of Georgia School of Law
  • Law Alumni Board, Emeritus, Georgetown University Law Center
  • Dean Rusk International Law Center Council, University of Georgia School of Law
  • Board of Advisors, Dean Rusk Center - International, Comparative and Graduate Legal Studies, University of Georgia School of Law
  • Distinguished Service Scroll Award, University of Georgia School of Law, June 2009
  • Chair, Washington International Tax Study Group 
  • Board of Trustees, The Langley School (McLean, Va), Chair (1999-2001) and Member (1994-2001)
  • American Society of International Law, Past Chair, Budget Committee, and Past Member, Budget Committee, Executive Committee and Executive Council, and International Taxation Correspondent-International Legal Materials
  • Fellow of the American Bar Foundation 
  • American Bar Association (Taxation Section)
  • International Fiscal Association