PROJECT SUMMARY Latinos are among the most heavily impacted communities by the COVID-19 pandemic in the US, with more than 3 times higher rate than non-Hispanic whites. To address this disparity, this team of investigators and community partners has established a multi-pronged approach that leverages the skill set of trusted bilingual/bicultural peer navigators (or promotoras) to address social determinants of health (SDOH) that create barriers to testing (such as lack of insurance, immigration status, stigmatization or loss of job/income), and to expand access to free COVID-19 testing in community settings. Our preliminary findings show that leveraging the promotora model for timely delivery of results (within 48 hours), paired with rapid linkage of COVID-19 positive patients to critical services (including clinical follow-up, food delivery, cash assistance, and/or isolation hotel), and referral of contacts for testing, increased acceptability and uptake of COVID-19 testing in a heavily impacted Latino community. The overall goal of this Phase I Testing Research Project called Juntos (Together) is to work closely with our community partners to systematically evaluate and refine current COVID-19 testing strategies, and to implement and evaluate innovative customized strategies to rapidly increase reach, access, acceptance, uptake, and sustainment of FDA-authorized/approved diagnostics (especially viral tests) for this highly vulnerable and health care marginalized community. Leveraging community partnerships and prior experience implementing an HIV testing campaign, we will develop and evaluate a customized Juntos COVID- 19 testing campaign to address specific common concerns in the Latino community and link users to existing Johns Hopkins COVID-19 community testing sites and to new options, including home-based and/or self- testing kits and rapid tests (Aim 1). To assess the overall impact of the Juntos COVID-19 Testing Project, we will rely on the latest in causal inference methods for evaluating population-level health interventions and implement a synthetic control analysis to compare testing uptake and positivity rate among Latinos in Baltimore City (intervention site) as compared to control zip codes across Maryland. (Aim 2). Finally, informed by Consolidated Framework for Implementation Research (CFIR) and RE-AIM framework, we will assess the implementation determinants, mechanisms, and outcomes of existing and novel Juntos testing interventions to inform future broad-scale implementation (Aim 3). We have assembled a multi-disciplinary team with methodological expertise in implementation science, community-based research, and laboratory medicine, and have a mature and long-standing collaboration with our partners at Esperanza Center, Casa de Maryland, the Mayor's Office of Immigrant Affairs, and religious leaders. Our team is enthusiastic to propose this implementation study to enhance access to testing for the Latino community, and will a...