OBJECTIVES: To investigate the characteristics of Chronic Hepatitis C (CHC) patients, their co-morbid conditions, treatments and associated costs using large health care payer databases.  METHODS: This retrospective study used data from Truven Health Analytics MarketScan databases from January 1, 2006-March 31, 2012. Adult patients with ≥2 diagnosis claims of chronic HCV (CHC) were selected. They had at least six months of continuous health plan and drug plan enrollment pre/post index date.  CHC patients were grouped by disease severity as non-cirrhotic disease (NCD), compensated cirrhosis (CC), or end-stage liver disease (ESLD). Co-morbidities, treatment rates, health care utilization, and cost were assessed by disease severity. RESULTS: 57,084 CHC patients met inclusion criteria, of whom 43,561 (76.3%) were NCD, 6,830 (12.0%) were CC, and 6,693 (11.7%) were ESLD. Mean age was 50.6 yrs [standard deviation (SD) =10.1]. 58.1% of patients were male and 73.8% had commercial insurance. Common co-morbidities included type II diabetes (DM) (13.3%), substance abuse (14.5%), and depression (11.7%).  Diagnosis of DM and substance abuse increased with disease severity (DM diagnosed in 14%/20%/27% and substance abuse in 20%/22%/26% of NCD/CC/ESLD CHC patients, respectively).  Detection of all three co-morbidities increased following HCV diagnosis.  Depression increased from 12% to 16% following HCV diagnosis. Anemia was highly prevalent following diagnosis (12.3%), especially in the ESLD cohort (28.3%). In the six months following HCV diagnosis, utilization of inpatient, hospital outpatient, emergency room, physician office, and pharmacy services increased significantly. During the study period, 10.9% of the population received treatment for HCV, 83.1% with dual therapy compared to 13.2% with telaprevir and 3.4% with boceprevir-based triple therapy. The modest use of the protease inhibitors likely reflects their coming to market in 2011. CONCLUSIONS: A small percentage of CHC patients receive treatment. DM, substance abuse, and depression are common among patients chronically infected with HCV. Health care utilization increased after CHC diagnosis.