Abstract There are approximately 43.5 million informal (unpaid) caregivers in the U.S., of which 5.6 million are African American.1 Almost one third of people living with HIV/AIDS (PLWHA) report receiving care from informal caregivers, typically friends and family.2 Informal caregivers often provide a variety of support to PLWHA, including emotional and instrumental, financial assistance, and health advice.3-5 African American caregivers of PLWHA have unique needs because they are more likely to experience stressors related to intersecting sources of stigma and discrimination related to HIV/AIDS and race18,19 and a lack of access to culturally sensitive health care providers and services,20-22 placing them at higher risk for burnout and adverse health outcomes for themselves and their care recipients.23 Thus, while informal caregivers play a critical role in supporting PLWHA, such caregiving can take a tremendous toll. Preventing or reducing caregiver stress is especially important in order to sustain informal caregiving and its myriad benefits for patients’ quality of life and health outcomes. Mindfulness-Based Stress Reduction (MBSR) is one type of intervention that has shown promise in helping caregivers manage stress while subsequently enhancing their mental health and well-being.9 MBSR consists of psychoeducation focused on stress reduction and the development of an accepting and non-judgmental attitude toward daily stressors of living.11 MBSR interventions can include activities such as guided meditations and yoga exercises designed to help individuals build awareness of the present moment, and decrease reactivity to stress.10-12,40 Building upon prior research regarding MBSR interventions, during Phase I, we successfully developed a prototype mobile application (app) for caregivers entitled Mindfulness Based Stress Reduction for African American Caregivers (MBSR-AAC). Based on the Health Stigma and Discrimination Framework,24 components of the app focus on decreasing stress associated with intersecting sources of stigma, discrimination, and caregiving burdens specifically associated with caregiving for PLWHA. In the present Phase II SBIR study, we will build on Phase I findings to incorporate research-driven enhancements to the app, conduct a feasibility trial of the enhanced app, and conduct a randomized clinical trial to examine the effectiveness of the app in reducing caregiver stress. If proven to be effective, the MBSR-AAC app could have a positive impact on the well-being of African American caregivers that serve as a critical pillar of support for many PLWHA.