Abstract Substance use disorder (SUD) disproportionately affects incarcerated people and increases HIV transmission risk among infected and at-risk populations. We will establish a Regional Research Hub (RRH) in greater metropolitan Atlanta to improve linkages to care for a recently incarcerated, HIV status-neutral group of individuals who experience SUD. Georgia leads the U.S. in correctional supervision (6.4% of all adults) and in HIV incidence (25.4/100,000). Only 2.7% of new HIV cases in Georgia are primarily attributable to injecting drugs. Historically, heroin has rarely been found in urine drug testing of persons arrested in Atlanta. Blacks are disproportionately jailed in Georgia, yet heroin use accounts for only 2% of admissions of Blacks to Georgia drug treatment facilities. Nevertheless, SUD pervasively contributes to HIV transmission. Although much NIDA-funded criminal legal research, such as the recent Justice Community Opioid Innovations Network initiative, has focused on opioid use, other substances are more associated with SUDs and HIV transmission in Atlanta. Given metro- Atlanta needs, we will address SUD more widely in our RRH’s drug-related HIV prevention and management efforts, using the situated Information, Motivation, Behavioral Skills model of Care Initiation and Maintenance. Specifically, we aim (1a) in years 1-2 of this project to conduct a pilot test of a previously developed intervention for linkage to/retention in care after jail via case management and peer navigation, SUCCESS-E. The intervention will be delivered to 60-100 persons with SUD in Fulton County Jail (FCJ) in an HIV status neutral manner. We plan to link Persons with HIV (PWH) to HIV care and Persons at High Risk of Seroconversion (PHRS) to PrEP care in combination with SUD treatment post release. In a randomized trial, we will compare linkage using SUCCESS-E versus treatment as usual; we will also gather cost data. Also, in years 1-2, we aim (1b) to conduct interviews of stakeholders in Fulton County, including study participants, for feedback on how well the intervention was adapted and implemented to meet the needs of persons with SUD, with or without HIV, who were leaving the jail. We will use the Consolidated Framework for Implementation Research to guide our interview script. Lastly in these years, we aim (1c) to form partnerships with jails and community stakeholders in 2-3 neighboring counties to gather information to revise and prepare for scale-up testing of the intervention in subsequent years. We will interview PWH/PHRS with SUD who are involved in the criminal legal system and jail administrators and other stakeholders to identify barriers and facilitators to implementing the intervention in these jurisdictions neighboring FCJ. In years 3-6, we aim (2) to conduct a Type I hybrid implementation-effectiveness trial among detained and released PWH/PHRS with SUD in multiple metro Atlanta counties. Using a stepped wedge trial design, we will ev...