The existence of mental health disparities has been confirmed in multiple studies in which African Americans are less likely than non-Hispanic whites to receive needed mental health services. Research has consistently shown that African Americans are underrepresented in outpatient mental health treatment settings and are over-represented in inpatient psychiatric settings. Further, African Americans are more likely to receive a diagnosis of schizophrenia and are less likely receive an affective disorder diagnosis during inpatient psychiatric hospitalization compared to non-Hispanic white patients, pointing to a need for examining factors contributing to mental health disparities in inpatient psychiatric settings. Using Andersen's Behavioral Model of Health Service Use, this study examined predisposing, enabling, and need factors differentially associated with health service utilization among African American and non-Hispanic white patients (n = 5183) during psychiatric admission. We conducted univariate and multivariate logistic regression analyses to examine both main effects and interactions. In the multivariate model, African American race at admission was predicted by multiple factors including younger age, female gender, multiple psychiatric hospitalizations, elevated positive and negative symptoms of psychosis, a diagnosis of schizophrenia, and substance use as well as having housing and commercial insurance. Additionally, screening positive for cannabis use at intake was found to moderate the relationship between being female and African American. Our study findings highlight the importance of examining mental health disparities using a conceptual framework developed for vulnerable populations (such as racial minorities and patients with co-occurring substance use).