Two widely-shared medical views motivate the proposed study: 1) Injuries to joints at some time in life can produce osteoarthritis in those joints later in life. 2) Perhaps the best predictor of future low-back pain is prior low-back pain. For our purposes, the time dimension is important. The initial injury or pain could occur on-the-job whereas the subsequent osteoarthritis or pain could occur much later, perhaps during retirement years. These subsequent osteoarthritis and pain events will generate direct costs (doctor visits, hospitalizations, drugs) and indirect costs (lost productivity on-the-job and in the home). Aim 1 is to estimate the costs of job-related osteoarthritis. Current estimates of all job-related injuries and illnesses ignore these costs. Aim 2 is to investigate the connection between employment in injury-producing jobs prior to retirement and functional disability after retirement. Costs of job-related osteoarthritis and functional disability in retirement are important for at least three reasons. First, ignoring them leads to a significant underestimate of the overall costs of job-related injuries and illnesses. Second, these costs were largely borne by victims, families, and taxpayers, not by workers' compensation (WC) systems. Third, current economic evaluations of some Occupational Safety and Health (OSHA) standards, such as those pertaining to ergonomics, also ignore these costs. If these standards reduce initial disorders and injuries, then they should also reduce the subsequent costs. The implication is that current ergonomic standards may be more cost-effective than is commonly believed. Prevalence and costs of osteoarthritis will be estimated with primary data from the National Health Interview Surveys, National Center for Health Statistics, the Bureau of Labor Statistics, and the Agency for Healthcare Research and Quality and with secondary data from published studies. We will present a range of estimates under clearly- stated assumptions so readers can select the scenario they find most reasonable. The connection between employment in injury-producing jobs and subsequent functional disability will be investigated with the National Health and Nutrition Examination Survey III (NHANES III). The NHANES III has information on the functional disability (Activities of Daily Living) of retirees, as well as information on subjects' longest held jobs prior to retirement.