One of the basic objectives of the workers' compensation program is prevention of work-related injuries and diseases. Most employees work for employers who are experience-rated (insurance costs vary with benefits paid). Preventive activities thus result in lower costs to employers. However, for the prevention stimulus to work, the program must pay benefits to workers whose disabilities are caused by the workplace. Scholars have concluded that many occupational diseases are not compensated by workers' compensation, thus undermining the basic preventive objective. The proposed research examines the factors that keep occupational diseases out of the workers' compensation program. In particular, the research examines (1) occupational disease cases that have been compensated and closed in New York State focusing on substantive outcomes such as the likelihood of litigation, duration in the system, and the amount of the award settlement, and (2) the procedures employed to reach these outcomes (e.g. diagnostic methods, adversarial proceedings, and negotiation of award settlements). The field research consists of a retrospective case study of closed occupational disease claims to establish a quantitative estimate of the magnitude of occupational disease cases reported through the workers' compensation system in New York State in comparison with nationally reported disease rate data. Demographic, socio-economic and personnel characteristics (e.g. age, sex, pre-injury wage, geographic location, industry and occupation) will be used to detect patterns in claim settlement for selected occupational diseases. A series of structured but open-ended interviews with administrators, lawyers, and physicians affiliated with the system will be used to construct a detailed set of descriptions of workers' knowledge of the claim filing process, causes for delay, excessive litigation and areas of scientific uncertainty. The research will identify statutory, administrative, or other features of the workers' compensation program that will expand coverage of occupational diseases.