OBJECTIVES:  Post-traumatic stress disorder (PTSD) is an anxiety disorder occurring after experiencing a traumatic event, and can lead to severe impairment of a patient's daily life. The study aims to assess the clinical and economic burden of PTSD in the US veteran population METHODS:  Patients diagnosed with PTSD (International Classification of Diseases, Ninth Revision, Clinical Modification code: 309.81) were selected from the Veterans Health Administration (VHA) database (October 1, 2010-September 30, 2014). The first observed PTSD diagnosis claim date was defined as the index date. Continuous medical and pharmacy benefits were required for the 12 months pre- and post-index date. The 10 most common comorbidities were calculated for the 12-month baseline period. The 10 most commonly prescribed medications in the 60 days post-index date were also calculated. Health care resource utilization (inpatient, outpatient, pharmacy) and costs (inpatient, outpatient, pharmacy, total) during the 12-month follow-up period were assessed and calculated. Descriptive statistics were calculated as means ± standard deviation (SD) and percentages to measure treatment, cost, and utilization distribution in the sample. RESULTS: For VHA PTSD patients (n=492,546), the most common comorbidities were hypertension (17.18%), depressive disorder (15.35%), diabetes (10.85%), anxiety (9.60%), and lumbago (9.58%). The most commonly prescribed medications were sertraline hydrochloride (14.54%), trazodone hydrochloride (12.54%), omeprazole (12.27%), citalopram hydrobromide (10.50%), and lisinopril (10.43%). The percentage of patients with inpatient stays (13.91%), outpatient visits (99.80%), and pharmacy visits (91.46%) was also calculated. PTSD patients incurred $5,486 (SD=$29,620) in inpatient, $10,057 (SD=$13,284) in outpatient, and $1,207 (SD=$5,817) in pharmacy costs. Total expenditures were observed at $16,750 (SD=$36,330). CONCLUSIONS: Results suggest that hypertension and depressive disorder are the most common comorbidities among PTSD patients. This disease was associated with high outpatient visit utilization, which translated to a high cost burden.