OBJECTIVES: The objective of this study is to compare prevalence of treatment for osteoporosis and identify predictors for osteoporosis treatment in elderly women residing in the community and in long-term care facilities. METHODS: This is a cross-sectional study using Medicare beneficiaries participating in the Medicare Current Beneficiary Survey (MCBS) between 2000 and 2003. The study population was female Medicare beneficiaries aged 65 and older with evidence of osteoporosis. The outcome variable captured drugs used to treat osteoporosis, including bisphosphonates, calcitonin, estrogens, parathyroid hormone analog and selective estrogen receptor modulator (SERM). The covariate of interest was an indicator of type of residence (i.e. commumity or long-term care facility) identified from survey data. RESULTS: The final study sample included 4,221 community dwellers and 394 facility residents with evidence of osteoporosis. The unadjusted prevalence of osteoporoses treatment was 52.1% for community dwellers and 40.9% for facility residents. However, after adjusting for other covariates, the adjusted prevalence of treatment was 52.0% (95% CI=[51.6%, 52.5%]) for community dwellers and 65.3% (95% CI=[64.9%, 65.7%]) for facility residents. The main factors that caused the flip in adjusted prevalence of treatment were age and limitations in activities of daily living (ADLs). Compared to patients aged 65-74, patients aged 75 and older were significantly less likely to be treated (AOR=0.81, 95% CI=[0.69,0.95] for age 75-84 and  AOR=0.54, 95% CI=[0.44, 0.67] for age 85 and older).  Each additional ADL reduced to odds of treatment by AOR=0.87, 95% CI=[0.64, 0.91].  CONCLUSIONS: The lower prevalence of osteoporoses treatment observed among community dwellers compared to facility residents is mainly due to differences in age and ADL limitations.  For elderly women with the same characteristics,  residents in long-term care facilities were actually more likely to receive osteoporosis treatment compared to their community counterparts over the study period.