As part of the push toward evidence-based mental health treatment, there is interest in increasing the proportion of patients who engage in evidence-based psychotherapy. However, attrition is a common phenomenon, especially at the beginning of psychotherapy. Using Veterans Health Administration (VHA) data, we examined psychotherapy utilization patterns among patients diagnosed as having a substance use disorder or posttraumatic stress disorder (PTSD) in fiscal year (FY) 2008. Start of a psychotherapy treatment episode was defined as the first psychotherapy visit after 60 days with no VHA psychotherapy visits within VHA. Thus psychotherapy visits more than 60 days apart were viewed as separate treatment episodes. This is consistent with a widely used definition of a treatment episode for a substance use disorder (1). Among patients who initiated psychotherapy, we also examined attrition—defined as attending only one or two psychotherapy visits.