In the United States, testing for HCV infection currently involves a two-step diagnosis process that is dependent on antibody testing — which can lead to underdiagnosis in populations with ongoing transmission. Current requirements for a prior test detecting HCV antibodies may be problematic in settings testing persons at higher risk for recent exposure/acute infection, such as syringe services programs and substance use treatment facilities, and for immunocompromised persons who may not have a reactive HCV antibody test. This project will assess the cost-effectiveness of one-step HCV testing versus the two-step HCV testing process to determine the best approach for early and reliable diagnosis of HCV infection.