Army Tactics, Techniques, and Procedures (ATTP) 4-33, "Maintenance Operations," describes Operating Force Maintenance Operations, and includes detailed information on how maintenance operations have changed with the transformation from a four-level maintenance system to two-level maintenance. It focuses on how maintenance operations are conducted at the operational and tactical-level. Its primary focus is on maintenance organizations and their missions, but also addresses the roles and functions of strategic level maintenance organizations that provide logistics and individual Soldier support services. The intended audience for this manual includes the following: Commanders at all levels - to give them a better understanding of how maintenance support operations are organized and provided; Commanders and Staff of sustainment organizations - to inform them of the integration of transforming maintenance support operations into Army missions; Soldiers of all grades - to give them a broad knowledge of the Army's tactical maintenance support operations structure and how it works. The manual applies to Active Army, the Army National Guard (ARNG)/Army National Guard of the United States (ARNGUS), and the United States Army Reserve (USAR) unless otherwise states.