Objective: HIV-positive individuals are at higher risk than healthy persons for agingrelated diseases, including myocardial infarction and non-AIDS defining cancers. Recent evidence suggests that HIV infection may modulate changes in the host cell epigenome, and these changes represent a potential mechanism through which HIV infection accelerates aging. We assessed the difference in DNA methylation (DNAm) age, an aging marker involving multiple age-related cytosine-guanine dinucleotide (CpG) sites, among antiretroviral treatment (ART)-naive HIV-positive and HIV-negative individuals in a cohort of veterans from the Veterans Aging Cohort Study. Design: Peripheral blood samples were collected from 19 ART-naive, HIV-positive, and 19 HIV-negative male participants, matched by age and race. Blood samples were collected from HIV-positive participants 7-11 years after ART initiation. Methods: We compared DNAm age between HIV-positive and HIV-negative groups at baseline and between HIV-positive patients at baseline and follow-up. We also performed an epigenome-wide analysis to identify CpG methylation sites associated with HIV infection. Results: DNAm age in HIV-positive individuals is, on average, 11.2 years higher than HIV study participants at baseline, and two of 10 HIV-positive individuals showed an increase in DNAm age after ART initiation. Epigenome-wide association studies showed an association of HIV infection with one site, in gene VPS37B, which approached statistical significance in our cohort (P=3.30×10 -6 , Bonferroni-corrected threshold=1.22×10 -7 ) and was replicated in a second, larger cohort. Conclusion: ART treatment-naive HIV-positive individuals have significantly older DNAm age compared to HIV-negative individuals in the Veterans Aging Cohort Study cohort. Longitudinal changes in DNAm age are highly variable across individuals after initiation of antiretroviral therapy.