This pamphlet lists 15 standards, and criteria to be met to reach those standards, used in accrediting American Montessori Society schools. Part 1, dealing with institutional stability, describes standards and criteria for school organization and administration, financial practices and procedures, physical facilities, enrollment policies, child records, personnel practices, community relationships, and transportation services. Part 2 concerns the Montessori developmental education program. It lists standards and criteria for school goals and philosophy, classroom policies and procedures, staff qualifications, material resources, program planning and implementation, organization of environments, staff behavior, and auxiliary programs. Criteria differ from those for other private schools in specifying procedures central to the Montessori curriculum (for example, each child's having the opportunity for individual activity for at least half of the school day, vertical age grouping, and the use of Montessori apparatus and "practical life" resource materials). (CB)