John Warren

John Warren is a highly experienced Medicare veteran with wide ranging experience in traditional Medicare fee-for-service, Medicare program integrity, and Medicare contracting issues.  With over 22 years of experience inside the Centers for Medicare and Medicaid Services (CMS), John brings a unique perspective to clients of all types and sizes.  As the former CMS director of the Divisions responsible for payment policy and program integrity, John is uniquely qualified to speak on matters related to Medicare payment for clinical laboratory services, Part B prescription drugs, and the Medicare physician fee schedule.


University of Baltimore, B.S., 1991

Representative Experience

  • Provide clients with seasoned and knowledgeable advice and opinion on proposed legislation and regulations affecting the Medicare program.
  • Advise a global specialty pharmaceutical manufacturer, on a large variety of issues related to drug coding, coverage and pricing.
  • Consult with an international pharmaceutical company, on coverage issues for new prescription drugs.
  • Work with the Diabetes Access to Care Coalition, on issues related to Medicare Competitive Bidding.
  • Assist the Medicare Dependent Hospital Coalition, on matters relating to disproportionate share hospital payment.
  • Represent a leading pharmaceutical company on matters related to the development of a new prescription drug


“CMS Take Steps to Modernize Clinical Lab Policies,” McDermott Will & Emery LLP On the Subject, Paul Radensky, M.D., John Warren and Eric Zimmerman, February 11, 2014.

“CMS Announces Plans to Modernize and Update the Clinical Laboratory Fee Schedule,” McDermott Will & Emery LLP On the Subject, John Warren and Eric Zimmerman, December 16, 2013.

“Drug Development and Regulatory Sciences Course,” University of California, San Francisco American, January 8, 2014

“Medicare Payment for Diagnostics,” Cambridge Health Institute, October 22, 2013

“Sweeping Changes to Medicare Payment for Clinical Laboratory Services”. National Law Review, Paul Radensky, John Warren and Eric Zimmerman, April 1, 2014.