Individual Trauma-focused CBT has been shown to be effective for treating posttraumatic stress disorder in military veterans. Treatment challenges are common including the presence of dissociation and comorbidities including depression, traumatic brain injury symptoms, substance misuse, and social transition difficulties. There are currently no standard psychological therapy guidelines for veterans with comorbid presentations. However, as recommended by the National Institute for Health and Care Excellence treatment guidelines, adapting existing treatments can improve the chances of successfully treating trauma cases. In line with these recommendations, the current case study describes how the existing individual trauma-focused CBT model was integrated to treat posttraumatic stress disorder with comorbid depression, persistent mild-traumatic brain injury migraine, and social transition difficulties in a 38-year-old male combat veteran. The client attended 16-sessions of trauma-focused CBT. This model integrated his comorbidities and involved his spouse and multidisciplinary discussions with his general practitioner, and neurorehabilitation team and the Veterans’ Transition Service. At the end of treatment, the client no longer met the diagnostic criteria for posttraumatic stress disorder. This case illustrates how trauma-focused CBT can be integrated to treat comorbid posttraumatic stress disorder in veterans.