Abstract: Posttraumatic stress disorder (PTSD) is a prevalent psychiatric condition, particularly among US Veterans. PTSD-diagnosed patients are more likely to experience suicidal ideation, suicide attempts and death by suicide when compared to non-PTSD-diagnosed patients. The US Department of Veterans Affairs (VA) emphasizes evidence-based psychotherapy (EBP) for PTSD, including prolonged exposure and cognitive processing therapy. This study focuses on how suicide risk impacts PTSD by evaluating utilization of nondifferentiated psychotherapy and EBP in a national sample of VA patients diagnosed with PTSD who died by suicide in 2017-2018. The study used a dataset of VA patients diagnosed with PTSD who died by suicide and received psychotherapy in the year before death (cases) and patients who had comparable diagnoses, demographics and received psychotherapy during the same interval and remained alive (controls). Cases and controls were matched on suicide risk (high, moderate and low). The study tracked nondifferentiated psychotherapy and EBP and analyzed cases and control utilization rates across risk-tiers. The final sample included high-risk (cases = 171; controls = 2052), moderate-risk (cases = 428; controls = 4280) and low-risk (cases = 53; controls = 529) patients. EBP utilization was markedly low, especially among cases. Higher proportions of moderate- and low-risk controls received EBP and received more sessions than matched cases. Even with VA efforts to promote EBPs, usage remains limited, particularly among patients who die by suicide. Further research is needed to understand utilization barriers and improve EBP delivery to better support PTSD-diagnosed patients and reduce their suicide risk.