Objectives: Early trauma exposure is common among young adults receiving public mental health services, posing increased risk for PTSD. While d supports the feasibility of PTSD screening, clinicians often fail to screen for PTSD in this population. This study aimed to examine the demographic factors, psychiatric comorbidity, and predictors of charted PTSD diagnosis among treatment-seeking young adults with positive PTSD screens in a community mental health care system. Methods: Screening for trauma history and PTSD symptoms was implemented among clients receiving community mental health services. There were 266 treatment seeking young adults (aged 18-35) endorsed at least one traumatic event and had a score of at least 45 on the DSM-IV PTSD Checklist (PCL), indicating probable PTSD. Results: Treatment-seeking young adults with positive PTSD screens were predominantly female (68%), minority (69%), and diagnosed with mood disorders (66%), with nearly 25% diagnosed with major depressive disorder. Of the young adults with positive PTSD screens (PCL >=45), only 15% had a chart diagnosis of PTSD. Variables significantly associated with a decreased likelihood of PTSD detection included a diagnosis of schizophrenia or bipolar disorder, exposure to fewer types of traumatic events, male gender, and white race. Conclusion: Routine PTSD screening and early trauma intervention for treatment-seeking young adults with mental health conditions should be prioritized to address the long-term impact of trauma. Keywords: schizophrenia, bipolar disorder, major depression, posttraumatic stress disorder (PTSD), trauma screening, community mental health care