This publication, "Health Service Support (Joint Publication 4-02)," provides doctrine for the planning, preparation, and execution of health service support across the range of military operations. The Military Health System supports the operational mission by fostering, protecting, sustaining, and restoring health. It also provides the direction, resources, health care providers, and other means necessary for promoting the health of the beneficiary population. The principles of health service support (HSS) consist of conformity, proximity, flexibility, mobility, continuity, and control. Conformity with the tactical plan is the most basic element for effectively providing health support. Medical planners must be involved early in the planning process, and once the plan is established, it must be rehearsed with the forces it supports. The principle of proximity is to provide health support to sick, injured, and wounded military personnel at the right time and to keep morbidity and mortality to a minimum. Flexibility is being prepared and empowered to shift medical resources to meet changing requirements. The medical commander must build flexibility into the operation plan (OPLAN) to support the combatant commander's (CCDR's) scheme of maneuver. The principle of mobility is to ensure that medical assets remain within supporting distance of maneuvering forces. Continuity of care and treatment is achieved by moving the patient through progressive, phased roles of care, extending from the point of injury or wounding to the US-support base. Each type of medical unit contributes a measured, logical increment of care appropriate to its location and capabilities. Control is required to ensure that scarce medical resources are efficiently employed and support the tactical and strategic plan. It also ensures that the scope and quality of medical treatment meet professional standards, policies, and US and international law. Health support is provided to military personnel by applying prevention, protection, and treatment capabilities. The five overarching joint medical capabilities for HSS are: first responder care capability, forward resuscitative care capability, theater hospitalization capability, definitive care capability, and en route care capability. This publication has been prepared under the direction of the Chairman of the Joint Chiefs of Staff. It sets forth joint doctrine to govern the activities and performance of the Armed Forces of the United States in joint operations and provides the doctrinal basis for US military coordination with other US Government agencies during operations and for US military involvement in multinational operations. It provides military guidance for the exercise of authority by combatant commanders and other joint force commanders (JFCs) and prescribes joint doctrine for education and training. It provides military guidance for use by the Armed Forces in preparing their appropriate plans. It is not the intent of this publication to restrict the authority of the JFC from organizing the force and executing the mission in a manner the JFC deems most appropriate to ensure unity of effort in the accomplishment of the overall objective.