A 5 year observational study is reported which reviews the implementation of the Geisinger Health System Osteoporosis Disease Management Program. This program includes Osteoporosis Clinical Practice Guidelines, physician and allied health care provider education, community education, and a bone density testing program. All women over the age of 55 years enrolled in the Geisinger Health Plan (GHP) from 1996 to 2000 were included in this analysis. The guidelines led health care providers to increase the evaluation of osteoporosis via bone density measurements and to increase the prescription treatment of osteoporosis. Most importantly, the age-adjusted incidence of hip fractures fell significantly in the entire group as well as in several age strata (65-74, 75-84 and 85+ years). Compared with a predictive model of no intervention, there was an overall reduction in health care costs to GHP estimated to be US$7.8 million over a 5 year period. This report is the first to suggest that an organized Osteoporosis Disease Management Program delivered by a health care system can result in increased evaluation and treatment of osteoporosis with a resultant significant decrease in hip fractures while decreasing the total direct costs of care to a health plan.