The purpose of this proof-of-concept program is to leverage existing health care institutions’ capacity to prevent, test for, treat, and cure Hepatitis C (HCV) in individuals with substance use disorder (SUD) and/or severe mental illness (SMI), particularly in communities severely affected by homelessness and to gain insights on effective ways to identify patients, complete treatment and reduce reinfection. • The program aims to support health care institutions in providing HCV prevention, testing, treatment, and cure services to individuals with SUD and/or SMI. • The program will provide funding for up to 40 awards, with an estimated total funding of $100,000,000. • The award ceiling is $7,500,000, and the award floor is $0. • Eligible applicants include States and Territories, political subdivisions of States, Indian tribes or tribal organizations, health facilities, or programs operated by or in accordance with a contract or award with the Indian Health Service, or other public or private non-profit entities.