OBJECTIVES:  Biologic Disease Modifying Anti-Rheumatic Drugs (bDMARDS) have revolutionized the treatment of rheumatoid arthritis. Biologic DMARDs are highly effective but demand extremely high costs. Understanding appropriate timing and risk factors for the use of bDMARDs is a concern for patients, physicians, and payers. The objectives were to identify, describe, and measure the risk factors associated with initiation of a bDMARD in newly diagnosed adult patients with RA between 2004 and 2013. METHODS: Patients were selected from a large national private insurance-claims database if they had at least 2 claims for ICD-9 code 714.xx at least 45 days apart and received DMARD therapy between 2004 and 2013. Predictors of initiation of a biologic included first line treatment regimen, ultrasound use, insurance plan generosity, disease severity, age, sex, comorbidities, and year of diagnosis. Cox Proportional Hazard models were used to evaluation the predictors associated with the initiation of a bDMARD. RESULTS:  A cohort of 20,731 patients with RA was selected, 64% were female, and the median age of onset was 54 years. Earlier initiation of a bDMARD was associated with dual therapy use vs. mono therapy (HR 1.27, 95% CI 1.17-1.38), ultrasound use 3-6 months before diagnosis (HR 5.46, CI 2.60-11.48), high plan generosity (HR 7.23, CI 6.60-7.91), disease severity (HR 1.12, CI 1.10-1.14), and year of diagnosis 2013 vs. 2004 (HR 2.09, CI 1.41-3.12). Protective factors included age at onset (HR 0.984 CI 0.981-0.987), comorbidities (HR 0.93, CI 0.91-0.95), and female sex (HR 0.92, CI 0.87-0.98). CONCLUSIONS:  Patients that initiated dual therapy, were younger, had more severe disease, had increased ultrasound use, had better drug benefit coverage, and were more recently diagnosed are more likely to initiate bDMARDs earlier in their disease history. Understanding these factors can help ensure bDMARDs are being used appropriately to achieve optimal therapies, and avoiding unnecessary costs and risks.