OBJECTIVES: To assess the clinical characteristics, utilization, and cost patterns of human immunodeficiency virus (HIV) patients in the U.S. veteran population. METHODS: A retrospective analysis was performed using the Veterans Health Administration (VHA) Medical SAS Datasets from October 1, 2005 to May 31, 2012.  All U.S. veteran beneficiaries diagnosed with HIV were identified using International Classification of Disease 9th Revision Clinical Modification (ICD-9-CM) diagnosis codes 042.xx and V08.xx. Descriptive statistics were calculated as means ± standard deviation (SD) and percentages to measure comorbidities, cost, and utilization distribution in the sample.  Health care resource utilization and costs were assessed for the 12-month follow-up period. Clinical status and laboratory tests were examined for the 12-month baseline period before disease identification. RESULTS:   A total of 10,873 patients were diagnosed with HIV from 2006 to 2011 in the U.S. veteran population. Common comorbidities included hypertension (n=1,047, 9.63%), depressive disorder (n=590, 5.43%) and diabetes mellitus (n=499, 4.59%). Outpatient services were utilized by 99.77% of HIV patients, followed by pharmacy visits (89.70%) and inpatient visits (27.67%).  Costs for outpatient ($13,338, SD=$15,709), pharmacy ($5,345, SD=$8,593) and inpatient services ($12,072, SD=$45,507) contributed to follow-up health care expenditures. The top three treatments for U.S. veteran HIV patients were sulfamethoxazole/trimethoprim, efavirenz/emtricitabine/tenofovir, and emtricitabine/tenofovir. Among 10,873 HIV patients, a total of 1,295 (11.91%) had CD-4 tests, of which 142 patients had values ≤50.  A total of 847 patients (7.79%) had the HIV viral load test, of which 194 patients had values >100,000. CONCLUSIONS: Sulfamethoxazole/trimethoprim, efavirenz/emtricitabine/tenofovir, and emtricitabine/tenofovir were the most frequently prescribed HIV medications. More research is required to better understand the economic benefits and adverse events of effective antiretroviral medications and regimens.