Effective HIV prevention among injection drug users (IDUs) requires educating the at-risk population about HIV transmission and risky behavior, and providing the means for behavior change. Current treatment for opiate dependence focuses on reducing the frequency of drug use. BUP/NX is a combination pill currently used to treat opiate-dependent individuals. This trial will evaluate the effectiveness of two therapies in preventing HIV transmission among IDUs. Drug and risk reduction counseling combined with either long term medication assisted treatment (LT-MAT) with BUP/NX or short term medication assisted treatment (ST-MAT) with BUP/NX will be compared in preventing the transmission of HIV among opiate-dependent individuals.