1 Severe maternal morbidity and mortality in the U.S. disproportionately affect African-American (AA) 2 women. Inequities occur at many levels, including community, provider/practice, and health system levels. The 3 parent funded award is testing the effectiveness and cost-effectiveness of a multilevel intervention to address 4 AA maternal morbidity and mortality in two Michigan counties: Genesee County (which includes Flint) and Kent 5 County (which includes Grand Rapids). Interventions were developed or co-developed by our partners in these 6 counties, who include AA women residents, enhanced prenatal and postnatal care (EPC) staff (including race- 7 matched community health workers), and physician/health system staff and providers. 8 Building on our work and the parent funded award, the objective of this supplement is to enhance the 9 understanding of the intersections of racism, residential segregation, other social determinants (e.g. 10 disparities in economic hardship, education), and a variety of other risk factors, on disparities in 11 maternal morbidity and mortality. This supplement will support the long-term goal of our interdisciplinary 12 program of research focused on the disproportionate burden of maternal morbidity and mortality that exists 13 among African American (AA) women, with the potential to reduce the large racial disparities in maternal 14 morbidity and mortality, especially between AA and non-Hispanic white (NHW) women. 15 The research is novel in its contribution to the field of research on the health of women of understudied, 16 underrepresented and underreported (U3) populations and in its use of a multidimensional framework with an 17 interdisciplinary approach to address disparities in maternal health. The supplement will increase the parent 18 project's overall impact by generating additional evidence that will contribute to the understanding of effective 19 interventions and pathways to reduce the large existing disparities in maternal morbidity and mortality. 20 The supplement will leverage funded parent award data from all Medicaid insured women who deliver in 21 Michigan from 2016-2021 (approximately 400,000 births, including 121,500 births to African American women). 22 Measures will be taken from a pre-existing linked dataset that includes Medicaid claims, death records, birth 23 records, and home visiting program data. The funded parent award is among the first to evaluate in a trial a 24 multilevel intervention to reduce AA maternal morbidity and mortality at the population level. The trial tests 25 whether the intervention engages the mechanisms presumed to underlie intervention effects and provides 26 cost-effectiveness data that systems need to make informed decisions about adoption, speeding implementation. 27 The analyses proposed in this supplement will improve the understanding of the mechanisms of the intervention 28 effects by investigating the intersection of a multitude of factors, both ...