Characterizing Intersectional Geospatial Stigma and Affirmation Landscapes and Their Influence on Black and Latino Bisexual Men At Risk for Substance Abuse and HIV - PROJECT SUMMARY Guided by Fundamental Cause Theory with innovative methodologies, this proposal examines the impact of geospatial intersectional stigma and affirmation on substance use and HIV risk among bisexual Black and Latino men. Bisexual men experience co-morbid health disparities including elevated substance use and HIV risk. Black and Latino men are disproportionately represented in bisexual populations relative to the general population in the United States making up 45% of bisexual men. Bisexual Black and Latino men experience elevated substance use and HIV risk relative to heterosexual Black and Latino men. One contributing factor is stigma. Intersectionality informs us that bisexual Black and Latino men experience a range of stigma types including binegative stigma based on their sexual identity, racist stigma, substance use stigma, and HIV stigma. While stigma is theorized to be multilevel and intersectionality experiences have called for geospatial examinations of stigma, few studies have sought to measure stigma geospatially. This proposal seeks to address these limitations by first collecting a general sample of adults to generate geospatial stigma scores then using ecological momentary assessment (EMA) to quantify activity space for a sample of bisexual Black and Latino men including momentary assessments of substance use and HIV risk. This will be addressed through 3 specific aims: Aim 1: Describe geospatial distribution of intersectional stigma in Cook County, IL and Palm Beach County, FL including bi-negativity, racism, substance use stigma and HIV stigma. Approach. We will generate geospatial stigma scores through a household-based probability sample of the general adult population (N = 2,000 ). Survey responses will be geocoded to generate geolocated averages of stigma scores. Hypothesis. There will be unequal distribution of stigma including areas of increased or decreased stigma. Aim 2: Examine the impact of geospatial stigma on the relationship between substance use and HIV risk. Approach. We will link geospatial estimates of stigma generated in Aim 1 to a second survey sample of HIV- Black and Latinx bisexual men using EMA to capture activity space (N = 600 ). Hypothesis. Bisexual men who reside or have activity spaces in areas with higher stigma will be more likely to use substance, and engage in HIV risk behaviors, while access to affirming social resources will buffer against geospatial stigmas. Aim 3: Analyze qualitative perspectives on the impacts of intersecting stigmas on substance use and HIV risk in bisexual men, provider interactions, and messaging. Approach. We will collect qualitative interviews with bisexual men (N = 48), and key informants (N = 24) addressing perspectives on the impact of stigma on substance use and access to HIV prevention and community services as well as preferences for prevention messaging. Findings will inform the development of multilevel intervention strategies.