OBJECTIVES: Recently, FDA is warning about the risk of hepatitis B virus (HBV) reactivation among hepatitis C virus (HCV) patients under direct-acting antivirals (DAA) therapy, who had current or previous HBV coinfection. Understanding HCV treatment pattern among HBV/HCV coinfected population is important. This study aimed to examine HCV treatment uptake for patients with HCV/HBV coinfection compared to HCV mono-infection. METHODS: A retrospective cohort study was conducted using Truven Health MarketScan Commercial Claims Database (2008-2014). Patients >=18 years old with newly diagnosed HCV and had no use of HCV treatment before the first HCV diagnosis (index date) were included. HCV/HBV coinfection was defined as any HBV diagnosis within 12 months prior to index date. HCV treatment uptake was compared between HBV/HCV co-infected and HCV mono-infected patients by multivariate logistic regression, controlling for age, gender, region, payer, drug abuse and comorbidities (e.g. HIV, cirrhosis, etc.). Treatment types and initiation time were compared by Chi-square tests and two-way ANOVA. RESULTS: A total of 60,538 HCV patients were identified, with 1.3% HBV/HCV co-infection (n=788, mean age= 52yrs, 69.5% male) and 98.6% HCV mono-infection (n=59,750, mean age= 53yrs, 60.0% male). Only 4.6% of co-infected patients (n=36) initiated HCV treatment, whereas 17.2% mono-infected patients (n=10,281) did. Among HBV/HCV co-infected patients, 44.4%, 36.1% and 19.4% received interferon/ribavirin, DAA plus interferon/ribavirin, and all oral therapy, respectively; the corresponding percentages were 40.8%, 35.4%, and 23.8% for HCV mono-infected patients (p=0.81). The average time (months) to initiating interferon/ribavirin, DAA plus interferon/ribavirin, and all oral therapy were 8.8, 17.6, and 13.8 for coinfection, and 7.5, 12.6, and 25.0 for mono-infection (p<0.05). After adjusting for baseline characteristics, HBV/HCV co-infected patients were 76% less likely to initiate HCV treatment (OR=0.24 95%CI 0.17-0.33). CONCLUSIONS: A lower rate of HCV treatment initiation was observed even in the era of direct-acting antivirals in HBV/HCV co-infected patients.