Abstract As mandated by legislation in 31 states, clinical mammographic breast density (MBD) information is currently disclosed to women identified as having heterogeneously or extremely dense breasts on routine mammograms (Breast Imaging-Reporting and Data System [BI-RADS] density categories of C/D, hereafter referred to as high MBD). The New York State legislation, enacted in 2013, informs women about the lower sensitivity of mammography and increased breast cancer risk associated with having dense breasts and advises them to seek risk assessment and additional screening; women with low MBD (BI-RADS density categories of A/B) do not receive density information. The legally mandated MBD information provided to women is ambiguous and written at a high literacy level. Additionally, any follow-up actions on this information taken by women require personal resources, including high educational attainment, health insurance coverage, and access to regular health care provider versed in breast cancer risk assessment and screening guidelines. We investigated the impact of this legislation on women's awareness of MBD, knowledge of its effect on breast cancer risk and detection, and communication with health care providers in a predominately Hispanic and foreign-born sample of 466 women, recruited from a mammography clinic in the Northern Manhattan community of New York City (age range: 40-60 years; 79% Hispanic, 12% African American; 81% foreign-born; 26% less than high school education). Overall 88% of the sample had obtained a prior mammogram since 2013 and 31% had heard about MBD. Awareness of MBD did not differ by risk factors for breast cancer (e.g., family history of breast cancer, breast biopsy, parity-related factors) or psychological factors related to breast cancer screening (breast cancer risk perception and worry). Non-Hispanic white women were significantly more likely to have heard of MBD (81%) than non-Hispanic African American (54%), and Hispanic women (13%). In multivariable logistic regression models, odds of MBD awareness were significantly lower in women who were Hispanic (OR=0.1, 95% CI: 0.04, 0.3 relative to white women), foreign-born (OR=0.3, 95% CI: 0.2, 0.6 relative to U.S.-born), or had lower educational attainment (e.g., OR=0.3, 95% CI: 0.2-0.7 for high school or less vs. college or higher degree). Women with personal high MBD were twice as likely as women with low MBD to be aware of MBD, but adjusting for personal MBD did not substantially alter the associations of race/ethnicity, education, and nativity with MBD awareness. In women who reported awareness of MBD, 47% and 76%, respectively, were able to correctly identify the higher risk and masking potential associated with high MBD, and 31% reported following on MBD information with their health care providers. Racial/ethnic and educational differences in knowledge of MBD impact and health care provider communication were smaller and less consistent. In conclusion, awareness of MBD remains low in women from racial/ethnic minority and lower socioeconomic backgrounds, even in a regularly screened population. These findings underscore the importance of understanding and averting potential unintended disparate consequences of breast density notification. Citation Format: Parisa Tehranifar, Carmen B. Rodriguez, Mariangela Agovino, Karen M. Schmitt. Breast density notification in a racially diverse and immigrant sample of women: Evidence for social disparities in awareness, knowledge, and follow-up [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr C82.