Housing First programs are promising approaches to transitioning substance using chronically homeless adults to affordable housing. However, Housing First programs need to provide support to residents to adjust to their changing social environments. The proposed project fulfills a critical gap by developing an electronic tool for a social network intervention using motivational interviewing techniques as well as results of a pilot test of the tool. The hypothesis to be tested is that Housing First residents who are given the intervention will be significantly more motivated to change their drinking, drug use, sexual risk behaviors, and social networks compared to controls receiving usual care.