Internalized stigma related to HIV is associated with poorer outcomes for people living with HIV (PLWH). However, little is known about the association between experiences of daily acts of discrimination by others and the activation of internalized stigma, including factors that may moderate this association. One hundred 9 men living with HIV responded to experience sampling method (ESM) questions 3 times a day for 7 days via smart-phones. ESM questions included experiences of recent acts of discrimination, internalized HIV stigma, avoidance coping with HIV, and recent social support. We also administered several traditional questionnaire measures assessing psychosocial constructs. In hierarchical linear modeling analyses controlling for age, race, socioeconomic status, and time on antiretroviral therapy, experiencing discrimination predicted internalized stigma within persons. Individuals higher on attachment-related avoidance, attachment-related anxiety, avoidance coping, perceived community stigma, and helplessness, and individuals lower on social support had stronger associations between discrimination and current internalized stigma. Similarly, results from 2 state moderator variables supported our trait analyses: State-level (ESM) social support and avoidance coping were significant moderators. Thus, when PLWH experience incidents of discrimination due to HIV, this may lead to increased feelings of internalized stigma. We extend the literature by demonstrating that the associations between experienced and internalized stigma are not just at the generalized trait level, but also occur at the state level, accounting for within-person variability. Results provide implications for interventions aiming to modify maladaptive interpersonal traits as well as interventions to increase social support to reduce the impact of discrimination on PLWH.