Osteoporotic fractures are common among postmenopausal women and elderly men, and they cause substantial direct medical costs and loss of quality of life. The potential costs of widespread intervention strategies to reduce the incidence of fractures are also quite high. Therefore, the cost-effectiveness of such interventions is highly significant to large-scale health insurers and healthcare systems. Most modeling studies to date have examined the cost-effectiveness of pharmacologic treatment for subsets of postmenopausal women selected on the basis of bone mineral density and/or prevalent vertebral fracture. They generally suggest that oral bisphosphonates and raloxifene are cost-effective therapies for these subsets. Increasingly, modeling studies of treatments for those selected on the basis of absolute fracture risk rather than bone density criteria are being done to establish absolute fracture risk thresholds at which various treatments are cost-effective.