Little is known about mental health services utilization among Iraq and Afghanistan veterans receiving care at Department of Veterans Affairs (VA) facilities. Of 49,425 veterans with newly diagnosed posttraumatic stress disorder (PTSD), only 9.5% attended 9 or more VA mental health sessions in 15 weeks or less in the first year of diagnosis. In addition, engagement in 9 or more VA treatment sessions for PTSD within 15 weeks varied by predisposing variables (age and gender), enabling variables (clinic of first mental health diagnosis and distance from VA facility), and need (type and complexity of mental health diagnoses). Thus, only a minority of Iraq and Afghanistan veterans with new PTSD diagnoses received a recommended number and intensity of VA mental health treatment sessions within the first year of diagnosis.