Contract health care plans exclude workers' compensation from among the prepaid medical benefits. Under present contract relationships, compensable injury and illness can be billed to the employer as fee-for-service care. The provision of health care, normally an expense for the prepaid health care provider, generates income when it is given under a compensation rubric. Per capita workers' compensation costs at eight federal shipyards range from less than $600 in yards with no health maintenance organization (HMO) coverage to more than $1,000 in yards with more than two-thirds of employees enrolled in prepaid health care plans. A statistically significant relationship between prepaid health care plan enrollment and per capita workers' compensation costs at these yards suggests the likelihood of systematic cost-shifting by overdiagnosis of compensable injury and illness. Changes in prepaid contract incentives may improve the ethical and economic health care climate for workers' compensation.