The enormous costs associated with physical and pyschiatric disability have camouflaged, in some ways, the utility of prevention in the area of disability. Overwhelmed by the needs of the severely disabled, funding and service agencies have been legislatively mandated to earmark their monies disproportionately for the most severely disabled rather than channeling funds toward early intervention services. The study described in this article is designed to measure the cost and health implications of an alternative allocation of resources for the disabled, to compare a secondary and tertiary prevention service. The preventive disability service that was tested was designed out of the results of a preliminary study of disability claimants, conducted at the same site. The study population was a sample of the claimants of the Health and Security Plan of a large urban union. Persons who filed claims with the Plan during 1974 were studied in terms of their demographic, employment and disability characteristics. High, moderate and low risk groups were identified; a specified subsample was targeted for testing the preventive service.