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.