 We hypothesize that integrating Hepatitis C into methadone and buprenorphine treatment will improve Hepatitis C outcomes as well as drug treatment outcomes in patients who are addicted to opiates. We will test this hypothesis by randomly assigning patients to receive integrated or separated care. The first group will receive Hepatitis C treatment and substance abuse treatment contemporaneously at the South Central Rehabilitation Center SCRC. They will take both methadone or buprenorphine and Hepatitis C medications under the daily methadone or weekly buprenorphine observation of a health care provider. The second group will receive substance abuse treatment at SCRC, and go to another facility to receive Hepatitis C treatment services. These participants will take their medications on their own without observation. 