Mary Louise Cohen

Mary Louise

Mary Louise Cohen

Washington, District of Columbia

Mary Louise Cohen, a founding partner of Phillips & Cohen LLP, has been called the “queen of qui tam” and recognized as one of the "500 Leading Lawyers in America" and “a legend for creating [the] qui tam/whistleblower practice.”


She has represented whistleblowers for more than 25 years in successful “qui tam” (whistleblower) lawsuits brought under the False Claims Act. Some of her most significant cases include:

Ms. Cohen received the Lifetime Achievement Award in 2013 for her work on whistleblower cases from Taxpayers Against Fraud Education Fund, a nonprofit whistleblower organization. Lawdragon has named her one of the "500 Leading Lawyers in America" several times on its annual list, most recently for 2014-2015. She also was included on “Best Lawyers” 2015 list and previous lists for Washington, DC.

Ms. Cohen graduated cum laude from Harvard Law School in 1977, where she was a member of the Harvard Legal Aid Bureau. From 1977 to 1981, she was an associate in private practice in Atlanta, Georgia, and Washington D.C.

Before specializing in representing whistleblowers, Ms. Cohen spent many years in public service positions. She served as counsel and chief counsel to the Subcommittee on Juvenile Justice of the U.S. Senate Judiciary Committee from 1981 to 1984. The following two years, she served as Legislative Director for a major public interest group in Washington, DC. From 1986 to 1988, she served as counsel to the Senate Judiciary Committee's Subcommittee on Antitrust, Monopolies and Business Rights.

Ms. Cohen co-founded The Batonga Foundation to support secondary education for African girls and the Aslan Project to improve survival for children with cancer in the developing world. She was a 2014 fellow at Harvard University’s Advanced Leadership Initiative.

Areas of Practice

  • Whistleblower/Qui Tam
  • Government Agencies & Programs
  • Government Contracts
  • Health & Health Care Law
  • Whistleblower -- Employee
  • Tax Law
  • Securities Law

Bar Admissions

  • California, 1989


  • Harvard University Law School, Cambridge, Massachusetts - 1977
    • Honors: Cum Laude
    • Honors: Member, Harvard Legal Aid Bureau

Published Works

  • "False Claims Can Result in Prison Time, Fines," (Co-Authored with John R. Phillips), Health Risk Management, June, 1997
  • "Failure to Disclose Medicare Overpayments or Accurate Information Can Result in Jail Time for False Claims," (Co-Authored with John R. Phillips), Health Fraud Litigation Reporter, June, 1997
  • "Failing to Report Medicare Billing Errors: A very Risky Business," (Co-Authored with John R. Phillips), New Perspectives (Journal of the Association of Healthcare Internal Auditors), Spring, 1997
  • "Civil War-Era Law Attacking False Medicare Claims," (Co-Authored with John R. Phillips), Healthcare Risk Management, March, 1997
  • "How to Avoid Liability Under the False Claim Act," (Co-Authored with John R. Phillips), American Medical News, February, 1997

Honors and Awards

  • Lifetime Achievement Award, Taxpayers Against Fraud, 2013
  • Washington’s Best Lawyers, 2013
  • "500 Leading Lawyers in America", Lawdragon, 2008

Past Employment Positions

  • United States Senate Judiciary Committee, Juvenile Justice Subcommittee, Counsel, Chief Counsel, 1981 - 1984
  • Senate Judicial Committee, Antitrust, Monopolies and Business Rights Subcommittee, Counsel, 1986 - 1988