The Mpowerment Project is a model community building and HIV prevention program that has been designed specifically to address the needs of young adult gay/bisexual men ages 18 – 29. It is the first documented HIV prevention intervention for young gay/bisexual men to succeed in reducing sexual risk behavior. The program has been developed, evaluated and continually refined by prominent behavioral scientists from the University of California, San Francisco's Center for AIDS Prevention Studies, the largest research center in the world dedicated to social, behavioral and policy science approaches to HIV.