Most analyses of racial and ethnic disparities in health care focus on individuals rather than organizations. Health care organizations may be a mechanism that produces disparities, if the representation of minorities within organizations’patient populations is associated with differential patterns of service delivery. This research considers whether the racial and ethnic composition of addiction treatment centers’caseloads is associated with the likelihood that organizations offer any prescription medications to treat addiction, psychiatric conditions, or pain. Data were collected from 288 publicly funded substance abuse treatment centers in the U.S. Logistic regression was used to estimate models of medication availability. The percentage of racial and ethnic minority patients was negatively associated with the odds of medication availability, even after controlling for organizational characteristics and patients’ diagnostic characteristics. Future research should continue to investigate how health care organizations may reduce inequalities in access to high-quality care.