The tendency for US blacks to report similar or lower rates of mental disorder than whites is well-established. However, whether these disparities are stable across cohorts of black and white Americans is not well understood. In the current study, we examined black-white differences in the lifetime prevalence of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, mood, anxiety, impulse control, and substance use disorders and any mental disorders across 3 cohorts of blacks and whites aged 4-18 years. Using merged data from the National Comorbidity Survey Replication (2001-2003) and the National Comorbidity Survey Adolescent Supplement (2001-2004), we observed a change in the black-white patterning of mental disorder between 1957 and 2004. Blacks born during 1957-1969 reported lower rates of anxiety disorders than their white counterparts (odds ratio (OR) = 0.69, 95% confidence interval (CI): 0.52, 0.91); blacks born during 1970-1982 reported no difference in the rates of anxiety disorders relative to whites (OR = 0.97, 95% CI: 0.76, 1.25); and blacks born during 1983-1991 reported higher rates of anxiety disorders than whites (OR = 1.30, 95% CI: 1.18, 1.43). Similar but less distinct trends were observed for mood disorders, impulse control disorders, and any disorders. Our results suggest that the black-white patterning of mental disorder in the United States has changed across cohorts, to the disadvantage of black Americans.