Background: In the United States, approximately 3 million people are infected with hepatitis C virus (HCV). Genotypes of HCV variably affect disease progression and treatment response. However, the relationships between HCV genotypes and liver disease progression, healthcare resource utilization, and healthcare costs have not been fully explored.Research design and methods: In this retrospective study of patients with chronic hepatitis C (CHC), healthcare claims from a large US health plan were used to collect data on patient demographic and clinical characteristics.Main outcome measures: Main outcome measures include healthcare resource utilization (HCRU) and healthcare costs. Linked laboratory data provided genotype and select measures to determine liver disease severity.Results: The sample (mean age 50.6 years, 63.5% male) included 10,331 patients, of whom 79.1% had genotype (GT)1, 12.8% had GT2, and 8.1% had GT3. Descriptive analyses demonstrated variation by HCV genotype in liver and non-liver related comorbidities, liver disease severity, and healthcare costs. The highest percentage of patients with liver-related comorbidities and advanced liver disease was found among those with GT3. Meanwhile, patients with GT2 had lower HCRU and the lowest costs, and patients with GT1 had the highest total all-cause costs. These differences may reflect differing rates of non-liver-related comorbidities and all-cause care. Multivariable analyses showed that genotype was a significant predictor of costs and liver disease severity: compared with patients having GT1, those with GT3 were significantly more likely to have advanced liver disease. Patients with GT2 were significantly less likely to have advanced disease and more likely to have lower all-cause costs.Limitations: Results may not be generalizable to patients outside the represented commercial insurance plans, and analysis of a prevalent population may underestimate HCRU and costs relative to a sample of treated patients.Conclusions: These results suggest that liver disease progression varies by genotype and that CHC patients with GT3 appear to have more severe liver disease. These findings highlight the importance of effective HCV treatment for all patients and support guidelines for treatment of high-risk patients, including those with GT3.