OBJECTIVES: Current osteoporosis therapies can reduce the risk of fractures and thus costs, but adherence to these medications is often poor.  We estimated yearly potential savings in fracture-related costs from improved adherence to osteoporosis therapies in Germany from a societal perspective. METHODS: The model was a deterministic cohort model estimating annual treatments and outcomes for German women aged ≥ 50 years old in 2010 (n=17,689,849), by f5 year cohorts.  Demographic parameters were drawn from government databases, medication prescription share from industry databases, fracture incidence (hip, clinical vertebral, and non-hip, non vertebral (NHNV)), medication adherence (medication possession ratio MPR, one year intervals) and efficacy from published literature.  As a base case we estimated 4.2% treated (n=745,313) with oral bisphosphonates (94.6%), strontium (2.7%) and raloxifene (2.6%); 54% with effective adherence (MPR >50%). Fracture related costs (excluding medication costs) included direct medical, long-term nursing care, and work loss. The model parameters are adjustable, allowing real time calculation of outcomes. We estimated current costs with 54% effectively adherent and 100% effectively adherent.  RESULTS: The model calculated total fracture-related costs for all patients in 2010 at €4.4 billion (with 69.6% for direct medical costs, 20.2% for long-term nursing care, and 10.2% for work loss). For the estimated 4.2% of treated patients, the model calculated total fracture-related costs at €184.9 million. Increasing the percentage of patients with effective adherence from 54% to 100% decreased costs for hip (16.2%), vertebral (24.4%) and NHNV fractures (6.3%). CONCLUSIONS: Adjustable parameters allow users to calculate yearly fracture-related costs and savings for different economic perspectives and decision options. According to one run using the above parameters, achieving full adherence to medication among women currently treated for osteoporosis in Germany would reduce fractures, and cut down annual fracture related costs by €27.8 million (15.1%).