OBJECTIVES: In a real-world setting, adherence to antiviral therapies is often subpar and treatment outcomes are consequently compromised.  This study evaluated the adherence rate to HCV therapy in a Medicaid population. METHODS: Patients eligible for this study were Texas Medicaid patients ≥18 years who had evidence of chronic HCV during the identification period (1/1/07 – 9/30/11) and were continuously enrolled throughout the assessment period.  Primary outcome was adherence to pegylated interferon (Peg-IFN) and telaprevir (TLV) or boceprevir (BOC) as measured by proportion of days covered (PDC) using refill history.  Univariate and multivariate logistic regression analysis evaluated predictors for adherence, such as age (<55, ≥55), gender, Charlson comorbidity index (CCI), race (Whites vs. Non-Whites), presence of medical/psychosocial comorbidities, number of prescription drugs and office visits (intervals of 10), and evidence of adherence to other chronic medications (coronary artery disease and diabetes). RESULTS: A total of 24,032 patients were identified as having chronic HCV; 9.4% with evidence of receiving HCV treatment.  Of those treated, 11.2% were initiated on therapy with either TLV or BOC in 2011.  The average HCV medication PDC was 70% with a significant difference between the first 12 weeks and the following 12 weeks of therapy (79% vs. 60%, p<0.001).  Significant positive independent predictors of HCV medication PDC greater than 70% included male gender (OR: 1.42, 95% CI: 1.08-1.86), higher number of non-HCV prescription drugs (OR: 1.11, 95% CI: 1.02-1.21) and higher number of outpatient visits (OR: 1.19, 95% CI: 1.08-1.31).  Age, CCI, race and adherence levels to other chronic medications were not significant independent predictors for HCV medication PDC.  CONCLUSIONS: Overall adherence for HCV therapy was poor (70%), especially after the initial 12 weeks of therapy (60%). Closer follow-up and management of other comorbidities may improve readiness to HCV therapy and improve treatment adherence.