OBJECTIVES: To understand the management of and costs associated with AD; To compare patient characteristics, healthcare utilization and costs in treated and non-treated patients newly diagnosed with AD in the US. METHODS: A retrospective database analysis examined patient and disease characteristics, AD treatment, and healthcare resource utilization among Medicare beneficiaries. The study included beneficiaries aged 65-100 years with 18 months continuous enrollment with medical and pharmacy benefits, a diagnosis of AD, and treatment with donepezil, galantamine, rivastigmine, or memantine; Healthcare resource utilization and costs between treated and untreated cohorts were evaluated during the 12 months prior to diagnosis (baseline period) and the 6 months following diagnosis (follow-up period). RESULTS: Of the total identified 9,812 incident AD patients, 57% percent (n=5,567) received an anti-dementia therapy during follow-up; Significant differences were observed between the treated and untreated cohorts at baseline in mean age (82 vs. 85), proportion of female gender (74 vs. 77%), and mean Charlson Comorbidity index score (3.29 vs. 3.56); At both baseline and follow-up periods, untreated patients had greater healthcare resource utilization and incurred significantly higher costs compared with treated patients. During the follow-up period, the unadjusted annual total Medicare cost per patient was US$31,670 and US$39,115 for the treated and non-treated cohorts, respectively. CONCLUSIONS: Forty-four percent of newly diagnosed patients are not treated with anti-dementia treatment during the follow-up period; Health care costs for non-treated AD patients are greater compared to treated AD patients, mainly driven by hospitalization, skilled nursing facility and hospice.