This field manual (FM) establishes command and control (C2) doctrine for the provision of Army Health System (AHS) support in echelons above brigade (EAB). It discusses all roles of care within the theater. The AHS is the overarching concept of support for providing timely medical support to the tactical commander. This publication is designed for use by medical commanders and their staffs that are involved in the planning and execution of medical operations in the EAB.