PROJECT SUMMARY/ABSTRACT Amidst disruptions stemming from the COVID-19 pandemic, including service interruptions and public health emphasis on stay-at-home orders, PWUD living with HIV may experience increased risk of suboptimal HIV treatment access and adherence outcomes. We are requesting an administrative supplement to examine the impact of COVID-19-related disruptions on PWUD living with HIV, focusing on treatment access and adherence, and organizational-level responses to the management of COVID-related risk. We propose to undertake this work in Vancouver, Canada, which is an ideal setting for the proposed research as it is characterized by: 1) a large population of PWUD living with HIV; 2) comprehensive and innovative HIV prevention and treatment interventions, which have also been implemented in other settings; and 3) ongoing National Institute on Drug Abuse (NIDA)-funded cohort studies of PWUD which facilitate our ethno- epidemiological research and ability to combine clinical and qualitative data. Building on our research infrastructure and experience studying HIV prevention and treatment among PWUD, we propose to examine the following aims: · AIM 1. To examine the impact of the COVID-19 pandemic, including public health measures such as stay-at-home orders and physical distancing, on co-management of HIV and other health conditions among PWUD living with HIV and complex comorbidities. · AIM 2. To identify systems-level barriers and facilitators to HIV treatment during the COVID-19 pandemic, including ART dispensation, particularly among people requiring HIV treatment assistance with complex comorbidities, and identify organizational adaptations made during the COVID-19 pandemic by HIV service organizations with comprehensive care models. 6