People involved in criminal justice systems experience high rates of homelessness and HIV risk following transition from jail to communities, compounded by significant medical and psychiatric comorbidity. Though housing, employment, and treatment for psychiatric and substance use disorders improve health outcomes and are stabilizing, services are frequently under-resourced, siloed and challenging to navigate. To address this need, the CHANGE (Comprehensive Housing and Addiction Management Network for Greater New Haven) initiative expands and enhances the local implementation of a community infrastructure that integrates housing, behavioral health, and addiction treatment services for highly vulnerable populations at-risk for or living with HIV, by virtue of their involvement in criminal justice systems and/or engagement in sex work. CHANGE responds to SAMHSA's Grants for the Benefit of Homeless Individuals (FOA TI-17-009) by developing an innovative model of integrated care that creates a "Patient-Centered Medical Home" (PCMH) for homeless, justice-involved people at-risk and living with HIV in New Haven, CT enrolling 50 people per year (250 in all). PCMHs provide care that is: comprehensive (including substance abuse and psychiatric treatment in primary care settings), patient-centered, coordinated between service providers, accessible (co-located services with expanded hours of operation), and high quality, all of which facilitates improved health outcomes. The CHANGE program develops a PCMH by: 1) creating and enhancing sustainable partnerships with co-location of services for HIV, HCV, substance abuse and behavioral health treatment using the Community Healthcare Van (a mobile medical clinic); the city's largest HUD provider who will provide harm reduction services, HIV prevention, housing coordination and navigation services; and the Connecticut Department of Correction; 2) fully engaging and retaining homeless people in quality primary care, mental health and substance use treatment; and 3) facilitating increased access to stable/permanent housing for people at-risk for or living with HIV who are transitioning from jail. CHANGE will achieve these goals by using evidence-based practices that include screening, brief intervention, referral to treatment (SBIRT), medication assisted therapies for opioid and alcohol use disorders (buprenorphine, extended-release naltrexone) with nursing-led interventions, network navigators, outreach on the Community Healthcare Van mobile medical clinic for early intervention, co-located and integrated services for HIV prevention and treatment with behavioral and substance abuse treatment, trauma-informed care, directly administered therapy, supported employment, and intensive case management that incorporates elements of the Assertive Community Treatment and Access to Community Care & Effective Services & Supports programs to increase engagement and sustain retention. CHANGE overcomes logistical and organizational constraints by immediately co-locating substance abuse treatment, HIV treatment and prevention, mental health and housing support services for people at-risk for or living with HIV who are justice-involved, rather than being constrained by geographical and brick and mortar restrictions.