Inmates face a disproportionate burden of HIV. This study sought to explore the relationship between social support and physical and mental well-being and the possibility that housing stability moderates this relationship among jail detainees living with HIV. Data for this cross-sectional analysis come from 438 clients who underwent a structured interview. Results indicate a significant positive relationship between social support and both types of well-being (ps < .05); the experience of homelessness was associated with less mental well-being (p < .01). There was no evidence of moderation. Results highlight the importance of social support and economic considerations in understanding well-being among HIV+ jail detainees.