Mr. Zimmerman is employed by the U.S. Army’s Joint Program Executive Office Armaments & Ammunition (JPEO A&A) as the Project Director Joint Services (PD JS),  responsible for integrating and coordinating the DoD's Single Manager for Conventional Ammunition (SMCA) mission; the SMCA's industrial base management and policy responsibilities to include a $2B+ (FY22-FY26) Army Ammunition Plant modernization program; industrial base strategic planning; implementing Public Law 105-261, Section 806; managing the Armament Retooling and Manufacturing Support (ARMS) program; managing a munitions manufacturing technology program; and managing a $500M+ (FY22-FY26) demilitarization program for all of DoD's missiles and conventional ammunition.

Prior to becoming PD JS in June 2020, he was Deputy PM Maneuver Ammunition Systems (MAS), responsible for the development, production and overall life cycle management of the US Army’s small caliber, medium caliber and tank ammunition programs.

Mr. Zimmerman established the PEO Ammunition Industrial Base Management Office in 2002 when the Office of PEO Ammunition was created.  In 2006, he merged with PD Joint Services as the Deputy PD Joint Services and absorbed the Air Force/Navy Bomb and Navy Ship Gun acquisition programs and continued to perform the Deputy PD JS duties through May 2017 before taking the DPM MAS position. Prior to PEO Ammunition, Mr. Zimmerman worked for the Office of the Under Secretary of Defense for Acquisition, Technology and Logistics as a Land Warfare Staff Principal, and was employed by the U.S. Army Armament Research Development and Engineering Center (ARDEC) where he held positions as the Associate for Engineering; Deputy PM of the Joint Service Small Arms Program; PM of the Objective Individual Combat Weapon and Objective Crew Served Weapon 20mm/25mm air bursting munition systems; and Project Engineer for small caliber ammunition design & development.

His international experience includes a tour with the Australian Army’s Engineering Development Establishment manufacturing the FN Minimi Light Support Weapon; participation in a variety of NATO working groups, and Chairs the OSD North American Technology & Industrial Base Organization (NATIBO) Munitions Working Group with Canada. Mr. Zimmerman received a B.S. in Mechanical Engineering from the Pennsylvania State University, a Master in Engineering from Stevens Institute of Technology, a Master in Technology Management from the University of Pennsylvania’s Wharton School & Moore School, completed the Harvard University John F. Kennedy School of Government Fellows program and graduated from the DAU’s Senior Service College-Fellows program. He is a certified Lean Six Sigma Black Belt and has attained Level III acquisition certification in Program Management and Systems Planning, Research, Development and Engineering.