Abstract HIV-infected patients frequently experience depression, drug use, and unstable housing but are often unable to access supportive services to manage these challenges. Data on barriers to needed supportive services are critical to improving patient access. Data from the Medical Monitoring Project (MMP), a national supplemental surveillance system for HIV-infected persons in care, was used to examine barriers to support service use and factors associated with need and unmet need for services. Interview data for 333 patients in care in 2007 and 2008 in Los Angeles County (LAC) showed that 71% (n=236) reported needing at least one supportive service and of these, 35% (n=83) reported at least one unmet need for services (46% Latino; 25% white; 83% male; 92% 30+; 77% gay/bisexual; 40% response rate). The main reasons that supportive services were not accessed included lack of information (47%; do not know where to go or who to call); an agency barrier (33%; system too confusing, wait list too long); or a financial/practical barrier (18%; too expensive, transportation problems). In a logistic regression that included all participants (n=333), African Americans (OR=3.1, 95% CI: 1.1-8.7) and those with incomes less than $10,000 were more likely to have service needs (odds ratio [OR]=3.5; 95% confidence interval [CI]: 1.3-9.3). Among those with at least one service need (n=236), those who were gay or bisexual were more likely to report at least one unmet service need (OR=2.8; 95% CI: 1.3-6.1). Disparities were found for need and unmet need for supportive services by race/ethnicity; income and sexual orientation. The reported reasons that services were not obtained suggest needed improvements in information dissemination on availability and location of HIV support services and more streamlined delivery of services.