Involuntary psychiatric treatment may parallel ethnoracial inequities present in the larger society. Prior studies have focused on restraint and seclusion, but less attention has been paid to the civil commitment system because of its diversity across jurisdictions. Using a generalizable framework, this study investigated inequities in psychiatric commitment. A prospective cohort was assembled of all patients admitted to an inpatient psychiatric unit over 6 years (2012-2018). Patients were followed longitudinally throughout their admission; raters recorded legal status each day. Sociodemographic and clinical data were collected to adjust for confounding variables by using multivariate logistic regression. Of the 4,393 patients with an initial admission during the study period, 73% self-identified as White, 11% as Black, 10% as primarily Hispanic or Latinx, 4% as Asian, and 3% as another race or multiracial. In the sample, 28% were involuntarily admitted, and court commitment petitions were filed for 7%. Compared with White patients, all non-White groups were more likely to be involuntarily admitted, and Black and Asian patients were more likely to have court commitment petitions filed. After adjustment for confounding variables, Black patients remained more likely than White patients to be admitted involuntarily (adjusted odds ratio [aOR]=1.57, 95% confidence interval [CI]=1.26-1.95), as were patients who identified as other race or multiracial (aOR=2.12, 95% CI=1.44-3.11). Patients of color were significantly more likely than White patients to be subjected to involuntary psychiatric hospitalization, and Black patients and patients who identified as other race or multiracial were particularly vulnerable, even after adjustment for confounding variables.