The Tactical Combat Casualty Care (TCCC) project begun by the Naval Special Warfare Command and continued by the U.S. Special Operations Command developed a set of tactically appropriate battlefield trauma care guidelines that were initially published in 1996. Transition of these guidelines into use throughout the Department of Defense has been ongoing since that time. The need for updates to the TCCC guidelines was recognized early on and has been carried out by the Committee on Tactical Combat Casualty Care established and operated by the Naval Operational Medicine Institute. The evolution of these guidelines from the 1996 recommendations to the present is described. Numerous reports in the medical literature and collected from combat first responders have documented that TCCC is saving lives on the battlefield and improving the tactical flow of missions on which casualties have occurred. Present challenges to the optimized implementation of TCCC in U.S. combat units include the need to expedite transition of new TCCC techniques and technologies to deploying units, to provide TCCC training for all U.S. combatants, and to ensure adequate funding for the Committee on TCCC.