The subject of this paper is a cost-element structure (CES) that identifies, defines and structures a list of cost elements that is intended to describe fully the life-cycle cost of any formal program, course, or device for individual training of military personnel. It was developed to satisfy a widely-recognized need for consistent and credible evaluation of cost in cost-effectiveness analyses of alternative methods of training. The cost-element structure is based upon authoritative and widely used cost guides promulgated by the Services and the Office of the secretary of Defense, and many potential users contributed to its development. Accordingly, the general use of a comprehensive CES such as this offers the following advantages. It should (1) ensure that all elements of life-cycle costs are accounted for, (2) reveal gaps in essential data, (3) permit making credible and equitable comparisons among training alternatives, (4) identify "cost drivers" for trade-off analysis or cost reduction, (5) enable resource specialists to focus on elements of interest, while observing the impact of those resources in a total-program context, (6) disclose significant variables for the development of cost-estimating relationships and, (7) improve communication and understanding among officials at various levels in the Services and the Office of the Secretary of Defense whose decisions affect the conduct of military training.