OBJECTIVES: We examined patient and county-level characteristics associated with advanced liver disease (ALD) at hepatitis C (HCV) diagnosis in three Medicare cohorts: 1) elderly born before 1945; 2) disabled born 1945-1965; 3) disabled born after 1965. METHODS: Data source was Medicare claims (2006-2009) linked to the Area Health Resource Files. ALD was measured over the period of 6 months before to 3 months after diagnosis. Using weighted multivariate modified Poisson regressions to address generalizability of findings to all Medicare HCV patients, we modelled the association between contextual characteristics and the presence of ALD at HCV diagnosis. RESULTS: We identified 1746, 3351, 592 patients with ALD rates of 28.0%, 23.0%, and 15.0% for birth cohorts 1), 2), 3). The prevalence of drug abuse increased among younger birth cohorts: 4.2%, 22.6%, and 35.6%, respectively. HIV co-infection (RR=0.63, p=0.001), dual Medicare/Medicaid eligibility (RR=0.89, p=0.017), residence in counties with higher median household income (RR range 0.82-0.86, p=0.009-0.065), higher density of primary care providers (RR range 0.84-0.86, p=0.022-0.041), and more rural health clinics (RR=0.90, p=0.084) were associated with lower ALD rates. End stage renal disease (RR=1.41, p=0.001), alcohol abuse (RR=2.57, p=0.001), hepatitis B co-infection (RR=1.32, p=0.004), and residence in the Midwest (RR=1.22, p=0.010) were associated with higher ALD rates. Living in rural counties with high screening capacity was protective in the elderly but associated with higher ALD rates among the disabled born 1945-65. Compared to Whites, Black race was associated with lower and Hispanic ethnicity with higher ALD rate only among the disabled born 1945-65 but not other cohorts. CONCLUSIONS: ALD prevalence patterns were complex and were modified by race, elderly/disability status, and the extent of health care access and screening capacity in the county of residence. These study results help inform treatment strategies for HCV in the context of coordinated models of care.