Objectives. To examine the extent to which differences in medication for opioid use disorder (MOUD) in pregnancy and infant neonatal opioid withdrawal syndrome (NOWS) outcomes are associated with maternal race/ethnicity.Methods. We performed a secondary analysis of a statewide quality improvement database of opioid-exposed deliveries from January 2017 to April 2019 from 24 hospitals in Massachusetts. We used multivariable mixed-effects logistic regression to model the association between maternal race/ethnicity (non-Hispanic White, non-Hispanic Black, or Hispanic) and prenatal receipt of MOUD, NOWS severity, early intervention referral, and biological parental custody at discharge.Results. Among 1710 deliveries to women with opioid use disorder, 89.3% (n = 1527) were non-Hispanic White. In adjusted models, non-Hispanic Black women (AOR = 0.34; 95% confidence interval [CI] = 0.18, 0.66) and Hispanic women (AOR = 0.43; 95% CI = 0.27, 0.68) were less likely to receive MOUD during pregnancy compared with non-Hispanic White women. We found no statistically significant associations between maternal race/ethnicity and infant outcomes.Conclusions. We identified significant racial/ethnic differences in MOUD prenatal receipt that persisted in adjusted models. Research should focus on the perspectives and treatment experiences of non-Hispanic Black and Hispanic women to ensure equitable care for all mother-infant dyads.