This United States Army manual, Army Techniques Publication ATP 4-42 Materiel Management, Supply, and Field Services Operations November 2020, provides supply personnel, logisticians, and leaders information on materiel management, distribution management, supply support, and field services support. It focuses on how staffs, supply units, and field services units support large-scale combat operations, incorporating themes from FM 3-0 and FM 4-0. It also addresses the Army Health System's medical logistics function specifically focusing on class VIII materiel management. This supply and services functions manual provides information on what Soldiers at the tactical, operational, and strategic levels need to know to make supply and field services support decisions. This manual describes the supply support process from an enterprise perspective, but it does not dwell on a single commodity or automated system. Of the field service functions it addresses only shower and laundry operations in detail as aerial delivery, field feeding, mortuary affairs, and water purification are covered in depth in separate Army techniques publications (ATPs). This publication addresses force health protection as it relates to preventive medicine and veterinary services support to class I materiel management, field hygiene, and sanitation as it relates to provision of field services. It also addresses the Army Health System's medical logistics function, to include a brief introduction to the medical units, with a focus on the class VIII supply support mission. Trainers and educators throughout the Army will also use this publication. The principal audience for ATP 4-42 is all members of the profession of arms. Commanders and staffs of Army headquarters serving as joint task force or multinational headquarters should also refer to applicable joint or multinational doctrine concerning the range of military operations of these forces.