Skills in emotional regulation are vitally important for enabling homeless young adults to navigate the complex and chaotic settings associated with homelessness. The current study seeks to test the construct, concurrent, and predictive validity of the Difficulties in Emotional Regulation Scale (DERS-18) in a sample of formerly and currently homeless young adults. Data come from a study of HIV risk among young adults who have experienced homelessness, including both those currently experiencing homelessness (n = 99) and in permanent housing (n = 120), collected between 2017 and 2019 in Los Angeles, CA. Structural Equation Modeling was used to complete Confirmatory Factor Analysis and Path Models focused on the relationship between mental health symptomatology and emotional regulation. Linear regression models tested the link between affective intensity and instability and the DERS-18. Model fit indices pointed to the five-factor solution of the DERS-18, excluding the Awareness subscale. Clinical scores of anxiety, depression, and PTSD were found to have a significant, positive correlation with DERS. Both intensity and instability of negative affect were associated with greater difficulty in emotional regulation, while the increased intensity of positive affect was associated with increased skills in emotional regulation. This study addressed several gaps in both homelessness and emotional regulation literature. The DERS-18 was found to have construct, concurrent, and predictive validity in our sample. Future work should consider the use of the DERS-18 to assess skills in emotional regulation, understand outcomes, and better tailor interventions for young adults who have experienced homelessness. (PsycInfo Database Record (c) 2021 APA, all rights reserved).