Abstract The Ryan White HIV/AIDS Program (RWHAP) for low-income people with HIV (PWH) is a key resource for reducing HIV health disparities and scaling up evidence-based interventions. As RWHAP serves >50% of US PWH, RWHAP outcomes are vital to achieving “getting to zero”/ Ending the HIV Epidemic (EHE) Plan targets. As a grantee for RWHAP Part A (RWPA) funding distributed to the counties/cities severely affected by HIV, New York City (NYC) conducts regular HIV care continuum monitoring citywide and in its RWPA programs, which offer support services to reduce social and behavioral barriers to care/treatment. Local data consistently show lower viral suppression (VS) among RWPA clients in HIV care than among non-RWPA PWH in HIV care. Relative to NYC HIV cases overall, NYC RWPA clients (~14,000 per year) over-represent Black and Latinx PWH and high-poverty neighborhoods. To address local outcome disparities and to fill gaps left by data-to-care (D2C) strategies and research focused on medical care (re-)linkage, we propose to implement and rigorously evaluate the effectiveness of a novel ‘data-to-suppression’ (D2S) intervention among ~1,300 RWPA clients in HIV care but unsuppressed. Surveillance-based reports on unsuppressed clients plus D2S capacity-building assistance will guide RWPA providers in targeting and delivering evidence-informed strategies to improve VS. Our proposed aims are to: 1) Measure D2S intervention effects on timely VS and time to VS, in a stepped- wedge hybrid Type 1 trial; 2) Identify modifiable determinants of D2S response, by comparing characteristics of D2S-exposed clients who do and do not achieve VS, to recognize opportunities to tailor and strengthen the intervention; 3) Assess D2S acceptability and participant preferences and priorities for its implementation, in eight (client and provider) focus groups and in a discrete choice experiment (DCE) with RWPA staff (n=200). This proposal answers the call in PAR-20-036 for research to deepen understanding of the broader context of VS, by leveraging extensive/multiple datasets and resources and applying implementation science methods to test an intervention to improve service delivery and ultimately achieve VS. The study is also aligned with the National HIV/AIDS Strategy goal to reduce health disparities – in this case, a VS gap between RWPA clients in care and other PWH in care in the same jurisdiction. The proposed study’s hybrid, Type 1 trial design supports rapid dissemination and uptake beyond NYC, should the intervention prove effective. Through the D2S trial, analysis of factors driving D2S response, and primary data collection in NYC RWPA support- service settings, the project seeks to clarify future intervention directions for low-income, Black and Latinx PWH, whose care continuum advances are vital for meeting 90-90-90, “getting to zero” and EHE Plan goals. The project’s potential impact is heightened in the time of COVID-19, given disproportionate burden of COVID...