This report presents a model developed to examine costs of public library services, such as reference, circulation, and special programs, to be used by librarians in implementing a program budget and planning a budget system. Allocations for personnel costs, materials costs, costs of supplies and services, technical processing costs, reference use of the circulating collection, and administrative costs are presented. Also included are tables showing breakdowns of individual personnel costs, time study sheets of library tasks, and personnel costs by function. (AP)