Purpose <p>To identify sociodemographic characteristics, prenatal healthcare utilization, and health factors associated with completed mental health screenings during pregnancy and postpartum, respectively.</p> Methods <p>We examined electronic medical records (EMR) data on documented perinatal mental health screenings from over 6000 patients who delivered singleton infants within one academic healthcare system in California between 2021 and 2023. Dependent variables included having at least one Edinburgh Postnatal Depression Scale (EPDS) score documented in the EMR during (1) pregnancy and (2) postpartum, among those who completed postpartum care within 12 weeks of delivery. We used univariate frequencies to determine rates of completed screenings and logistic regression models to identify patient characteristics associated with completed screenings in each time period.</p> Results <p>Overall, 67% of patients completed screenings in pregnancy and 56% completed screenings in postpartum. In pregnancy, patients who were White, multiparous, did not prefer English, began prenatal care in the third trimester, and completed 10 or fewer prenatal care visits each had lower odds of completed screenings than their counterparts. In postpartum, patients who were White, privately insured, had vaginal deliveries, and had term births (at least 37 weeks of gestation) each had lower odds of completed screenings than their counterparts.</p> Conclusions <p>Although California law requires perinatal mental health screening in pregnancy and postpartum , the identified inequities in screening suggest additional efforts are needed to ensure all perinatal patients are screened for mental health in accordance with the law. These efforts should be tailored to the populations least likely to be screened in order to achieve universal perinatal mental health screening.</p>