This journal article describes a study that sought to identify predictors of a young person’s first episode of homelessness during the 12 months after substance use treatment entry. The researchers used data from a longitudinal study of adolescents (n=17,911; aged 12 to 17 years) receiving substance use treatment throughout the U.S. The participants completed surveys at intake and at 3-, 6-, and 12-month intervals after intake. After excluding adolescents who reported previous experiences of homelessness, 5% of the study participants reported their first episode of homelessness over the 12 months after treatment intake. The final models indicate that those who were older, male, reported more victimization experiences, mental health problems, family problems, deviant peer relationships, and substance use problems (more treatment episodes and illicit drug dependence) were more likely to report experiencing homelessness. The findings show that Hispanic/Latino adolescents were less likely to experience homelessness compared with white adolescents. The results point to the important risk and protective factors that can be assessed at treatment entry to identify adolescents at greater risk of experiencing their first episode of homelessness. (author abstract modified)