This Field manual (FM) describes how logistics operations take place in the Brigade Support Area of Operations. It is primarily focused on how the brigade support battalion (BSB) performs its mission, but it also addresses the roles and functions of other sustainment elements within the brigade combat team (BCT) as well as those organizations external to the BCT that provide logistics and individual Soldier support services. This field manual was written for BSB staff officers and non-commissioned officers. Knowing that many are assigned to battalion staffs prior to advanced formal education, this manual provides all a general idea of functions performed by each unit and staff section assigned to the BSB. Chapter 1 is a review of modular force logistics and the various types of brigade combat teams and support brigades; Chapter 2 explains the role of the BSB, including the headquarters company and staff, and briefly describes the role of the Aviation Support Battalion (ASB); Chapter 3 covers the organizational structure and function of the distribution Company; Chapter 4 covers the role and organization of the field maintenance company; Chapter 5 provides detailed information on the brigade support medical company; Chapter 6 describes another key component of the brigade support battalion-the forward support company. Logisticians and Soldier support specialists, enabled by technological advances, provide support essential to the BCT during the full spectrum of military operations: offense, defense, stability operations, and civil support. Sustainment facilitates uninterrupted BCT operations, and it is carried out through the replenishment of supplies, maintenance of equipment, and performance of other services. BCTs have a significant organic capability to sustain their own operations, which serves to ensure freedom of action, extend operational reach, and prolong endurance.