Mark E. Warren

Mark E. Warren



Worked on every major tax-policy debate since the Clinton administration. Relied upon by businesses to develop effective tax strategies, from corporate and international to energy and environmental policies.

Mark Warren is a well-respected professional on the Hill, having spent more than two decades serving as congressional tax counsel spanning four administrations. Most recently, Mark served as chief tax counsel to the Senate Finance Committee, where he handled the development and implementation of Chairman Chuck Grassley’s (R-IA) tax agenda, including advising on all aspects of federal tax, retirement, pensions and tax-administration policy. He also contributed to the development and drafting of key parts of the Tax Cuts and Jobs Act (TCJA) as senior tax counsel in the office of Sen. John Thune (R-SD). 

At Brownstein, Mark works closely with companies from startups to multinationals to develop effective tax strategies to achieve business priorities. He also focuses extensively on energy and environmental tax policy.

Prior to Brownstein, Mark spent four years as tax counsel to the House Ways and Means Committee under committee chairmen Dave Camp (R-MI), Paul Ryan (R-WI) and Kevin Brady (R-TX). He also served as deputy assistant secretary of the Department of the Treasury, Office of Legislative Affairs in the administration of President George W. Bush. In addition to his public service, Mark spent two years as vice president for tax and finance at the Retail Industry Leaders Association and practiced law in New York and Washington, D.C.

Insights & Publications



  • LL.M., 1992, New York University School of Law
  • J.D., 1989, Georgetown University Law Center
  • B.S., 1986, Georgetown University


  • New York
  • Washington, D.C.