Jonathan S. Klarfeld


  • JD, cum laude, New York University School of Law, 1995; articles editor, Annual Survey of American Law
  • AB (English and American Literature and Public Policy and American Institutions), magna cum laude, Brown University, 1992; Phi Beta Kappa


  • District of Columbia, 2015
  • New York, 1997

Court Admissions

  • U.S. District Court for the Eastern District of New York
  • U.S. District Court for the Southern District of New York
  • U.S. Court of Appeals for the Sixth Circuit
  • Honorable Frederic Block, U.S. District Court for the Eastern District of New York
  • Legal 500 (2016-2017)

Jonathan S. Klarfeld


Jonathan S. Klarfeld is a veteran antitrust enforcer who led many significant merger investigations and challenges during his 13 years at the Federal Trade Commission’s Bureau of Competition in Washington, D.C. Jonathan brings to Ropes & Gray clients a broad range of experience and knowledge about how antitrust reviews of transactions proceed, how consents are reached and how matters are litigated.

A staff attorney with the FTC from 2000 to 2008, Jonathan was named counsel to the director in 2008, where he oversaw several merger and non-merger divisions within the FTC. In 2009, Jonathan was appointed a Deputy Assistant Director in the Mergers I Division. In that role, he managed all aspects of the antitrust enforcement division in case selection, oversight and enforcement recommendation development. He also oversaw and participated in investigational hearings and depositions, negotiated consent agreements and litigated matters across a wide range of industries. Jonathan has supervised and led milestone antitrust cases, including, most recently, the commission’s enforcement actions in Omnicare/PharMerica and Nielsen/Arbitron and its investigation of Express Scripts/Medco.

During his time at the FTC, Jonathan was detailed to the U.S. Attorney’s Office for the District of Columbia where he served as a Special Assistant U.S. Attorney, trying several cases and participating in all aspects of criminal prosecutions, including arraignments, plea negotiations, trials and oral arguments, witness preparations and sentencings.

Jonathan began his legal career in private practice as a litigation associate at Reboul, MacMurray, Hewitt, Maynard & Kristol.


  • Represented Pfizer before the FTC in its $17 billion acquisition of Hospira.
  • Represented TPG Capital, L.P. before the FTC in its sale of Par Pharmaceuticals to Endo International plc.
  • Represented Berkshire Partners before the DOJ in connection with the acquisition of Fibertech Networks by Berkshire’s portfolio company Light Tower Fiber Networks. The acquisition closed without a Second Request.
  • Represented Key Food Stores Co-operative, Inc. before the FTC in its acquisition of 23 stores from The Great Atlantic & Pacific Tea Company (A&P), arising out of A&P’s bankruptcy proceeding.
  • Represented a third party in the FTC’s investigation and litigated challenge of Steris Corporation’s $1.9 billion acquisition of Synergy Health plc.
  • Represented Wright Medical Technology, Inc. before the FTC in connection with its $3.3 billion merger with Tornier N.V. The transaction closed with divestitures representing less than $15 million in revenue.
  • Represented Welsh Carson Anderson & Stowe and its portfolio company United Surgical Partners International (USPI) before the FTC relating to USPI’s combination with Tenet Healthcare. The transaction closed without a Second Request.
  • Represented Medtronic before the FTC in its acquisition of California startup Twelve Inc.
  • Represented HealthSouth Corp. in its acquisition of CareSouth Health System Inc., a private provider of home health services.



  • Panelist, American Bar Association Section of Antitrust Law, “Recent Developments in Health Care & Pharmaceuticals,” Washington, DC (May 2018)
  • Panelist, “Generic Drug Pricing – Are Consolidation or Cartels to Blame,” ABA Section of Antitrust Law, Pricing Conduct Committee, (November 18, 2016)
  • Panelist, “What's New in Health Care Antitrust: Multiregional Networks, Physician Acquisitions, and Vertical Theories of Harm,” The American Health Lawyers Association (March 2016)
  • Speaker, “Conditional Pricing Arrangements Explored,” The Knowledge Group (January 2015)
  • Panelist, “Better Decision Making Through Analysis of Litigation Risk,” GOAL’s Global Compliance & Risk Management Conference and Exhibition (November 2014)
  • Panelist, “Blurred Lines: Intersection of Antitrust and Consumer Protection in Healthcare Markets,” ABA Section of Antitrust Law, Health Care and Pharmaceuticals, Advertising Disputes and Litigation, and Consumer Protection Committees (July 29, 2014)
  • Panelist, “Future Forecasting in Potential Competition: Stormy Days or Clear Visibility,” ABA Section of Antitrust Law, The Mergers & Acquisitions Committee (February 4, 2014)
  • Panelist, “Express Scripts-Medco: The FTC Decision and Analysis,” ABA Section of Antitrust Law, Health Care & Pharmaceuticals and Insurance & Financial Services Committees (May 30, 2012)