ABSTRACT Black perinatal women face significant mental health disparities. In particular, Black women are at increased risk for trauma and stressor-related disorders, which have been shown to be associated with significantly increased risk for severe maternal morbidity. Few Obstetric departments screen patients for trauma and stressor-related disorders, and Black women are less likely to be insured and have access to perinatal care. To begin to address disparities in unmet trauma and stress needs among Black perinatal women, we propose a sequential mixed-method study with three aims: (1) utilizing data from the National Survey on Drug Use and Health (NSDUH), identify determinants of mental health treatment utilization and unmet mental health needs among a national sample of Black women of reproductive age (18-44 years) with serious psychological distress; (2) to contextualize findings from Aim 1, use the patient-centered access framework to analyze data from 5 focus groups with Black perinatal women living in two urban areas (n=40) to understand barriers and facilitators to accessing perinatal mental health supports and recommendations to improve access; and (3) conduct semi-structured interviews with 20 OB providers and administrators from two urban, safety-net hospital systems serving primarily Black patient populations to assess provider and systems-level barriers and facilitators to conducting trauma and stressor-related disorder screenings and referrals. Achieving the aims of this study will lead to the identification of multilevel barriers and facilitators to addressing unmet mental health needs among Black perinatal women who experience trauma and stress. By utilizing a mixed-methods approach that integrates national estimates with contextualized patient, provider, and administrator perspectives, this study will generate targeted policy and program-based recommendations to promote access to trauma and stressor-related disorder screenings and services for Black perinatal women in order to reduce disparities in maternal morbidity.