Women living with HIV (WLWH) in the U.S. are more than twice as likely to die of breast cancer compared to women without HIV. Although WLWH are less likely to obtain mammography than women without HIV, research examining risk factors for non- adherence to screening among WLWH is limited, particularly among those aged 50-74 years for whom biennial screening is currently recommended. This project examined risk factors for non-adherence to screening mammography among WLWH aged 50-74 receiving primary care at UC San Diego and UC San Francisco between 2016 and 2018. This study used electronic medical record data to compare rates of adherence to mammography guidelines between WLWH and the general population of women in California (Aim 1). Logistic regression analyses were conducted to evaluate individual (i.e., age, race/ethnicity, medical and psychiatric co-morbidities, smoking status, HIV- related medical characteristics), interpersonal (i.e., marital status, PCP department, PCP relationship length, number of office visits), and organizational (i.e., insurance, healthcare site) factors associated with non-adherence to recommended mammography screening among WLWH (Aims 2, 3, 4). Multiple logistic regression was used to identify the unique contribution of variables identified in Aims 2, 3, and 4 in predicting non-adherence to screening mammography and to determine the influence of individual, interpersonal, and organizational variable(s) on model fit (Aim 5). WLWH (N = 293, mean age = 57.4, 36.2% non-Hispanic White) were significantly less likely to obtain mammography screening than the general population. WLWH at greatest risk for non-adherence to mammography screening included those with mental health or substance use diagnoses, Hispanic women, and women who engaged in fewer office visits. In adjusted analyses, WLWH with a mental health diagnosis were more than twice as likely to be non-adherent with screening recommendations than their peers, and Hispanic women were twice as likely to be non-adherent than non-Hispanic White women. The inclusion of interpersonal, but not organizational, variables significantly improved model fit. Evidence-based interventions are needed to increase adherence to mammography screening among WLWH. Such interventions have the potential to increase the uptake of timely breast cancer screening and decrease breast-cancer related morbidity and mortality among this medically vulnerable population.