Abstract Background: Neighborhood deprivation is hypothesized as a potential driver of racial disparities in breast cancer mortality. However, research shows that neighborhood deprivation is associated with increased breast cancer mortality among White women, but has little to no association among Black women. No study has previously considered the intersections of race, social cohesion, or urban/rural status in the association between neighborhood deprivation and breast cancer mortality. Methods: Neighborhood deprivation was examined in relation to breast cancer mortality among 31,358 non-Hispanic Black and non-Hispanic White women diagnosed with invasive breast cancer (stage I-IIIA) between 2010-2017, followed through 2019, and identified by the Georgia Cancer Registry. Two composite scores, the Area Deprivation Index (ADI) and neighborhood deprivation index (NDI), were used to characterize neighborhood deprivation. A third composite score, the Yost index, was assessed as a measure of neighborhood socioeconomic status (SES). Each composite score was composed of factors representing six domains: poverty, income, occupation, housing, employment, and education. Data on ADI were obtained from the Neighborhood Atlas and was assessed in deciles. American Community Survey data from 2011-2015 and principal components analysis were used to derive the NDI and Yost index. Both measures were assessed in quartiles. Each composite variable was measured at the block group level and linked to patient data. Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between each composite variable and breast cancer mortality, overall and by race/ethnicity. Intersectionality will be examined by considering the joint effects of race/ethnicity, social cohesion, and urban/rural status. Results: During the 9-year follow-up period, 2,353 (1,347 non-Hispanic White, 1,006 non-Hispanic Black) women died from breast cancer. Regardless of which composite score was assessed, living in the most deprived or lowest SES neighborhoods was associated with an increased risk of breast cancer mortality in models adjusted for age and race (ADI decile 10 vs. 1: HR=1.57, 95% CI 1.26-1.96; NDI quartile 4 vs. 1: HR=1.43, 95% CI 1.26-1.63; Yost index quartile 1 vs 4: HR= 1.34, 95% CI 1.18-1.51). Stratification by race/ethnicity showed associations were slightly stronger among non-Hispanic White women but null among non-Hispanic Black women. Results from analyses examining the joint effects of race/ethnicity, social cohesion, and urban/rural status are forthcoming and will be presented in December. Conclusions: Consistent with previous studies, our study found that living in a deprived neighborhood may increase breast cancer mortality among non-Hispanic White women, but not non-Hispanic Black women. Investigating the association with an intersectionality framework may help identify subgroups of women who are particularly susceptible to the adverse impact of neighborhood deprivation on breast cancer mortality. Citation Format: Lauren E. Barber, Jasmine M. Miller-Kleinhenz, Maret L. Maliniak, Leah Moubadder, Jeffrey Switchenko, Lauren E. McCullough. Neighborhood deprivation and breast cancer mortality among Black and White women [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD1-03.