OBJECTIVES: To describe annual costs of etanercept, adalimumab and infliximab per treated patient across adult indications using real-world US drug data. METHODS: IMS LifeLink™ Health Plan Claims database was used to identify adult patients (≥18y) with ≥1 claim for etanercept, adalimumab or infliximab between January 1, 2005-March 31, 2009 (first TNF-blocker claim in study period is index claim); patients who were biologic-naïve or continuing TNF-blocker treatment were included. Patients had to have 360 days continuous enrollment following index claim and 180 days prior to index claim (pre-index period). In the pre-index period, patients were included if they had a diagnosis of rheumatoid arthritis, psoriasis, psoriatic arthritis, or ankylosing spondylitis, but were excluded if they had a diagnosis of Crohn’s disease or ulcerative colitis. Patients were followed for 1-year. Mean monthly dose was computed for patients on therapy; wholesale acquisition costs were applied to mean monthly dose and Medicare Physician Fee Schedule was applied to related drug administrations. Costs from restarting index TNF-blocker therapy after discontinuation and costs from switching to a different TNF-blocker were attributed to patients’ index therapy. RESULTS: Overall, 27,704 patients (14,777 etanercept, 6,862 adalimumab, 6,065 infliximab), were identified. The indication mix was 65% rheumatoid arthritis, 11% psoriasis, 13% psoriatic arthritis, 5% ankylosing spondylitis, and 6% with multiple indications. The 1-year mean cost per treated patient for all patients was lowest for etanercept, $14,013, followed by adalimumab, $17,716, then infliximab, $20,665. For biologic-naïve patients, mean cost per treated patient was $13,342 for etanercept, $16,718 adalimumab, and $18,589 infliximab. For patients continuing biologic therapy, cost per treated patient was $14,438 for etanercept, $18,816 adalimumab, and $21,846 infliximab. CONCLUSIONS: When comparing TNF-blocker cost per treated patient across adult indications, etanercept has the lowest cost per treated patient compared to adalimumab and infliximab when using actual drug utilization data from US commercially-insured population.