PROJECT SUMMARY Breast cancer is the second leading cause of cancer-related death and the leading cause of premature mortality for women in the U.S. Women who are racial/ethnic minorities experience an unequal burden of the disease. Breast cancer screening mammography guidelines for women aged 40-49 years are controversial. The potential benefit of avoiding an advanced cancer is often emphasized, while minimizing the frequency of possible harms. Conflicting recommendations for age at initiation and frequency of screening mammography for women aged 40-49 years highlight concerns related to the benefits and harms of screening. These conflicting recommendations leave women confused about when to initiate screening, how often to be screened, what sources to trust, and can undermine informed decision-making about screening mammography. Women from diverse racial/ethnic groups and those with limited health literacy are particularly vulnerable to misunderstanding screening recommendations. Health literacy is the degree to which one has the ability to obtain, process, understand, and use health information and services in order to make appropriate health decisions. Those with limited health literacy have difficulty navigating the health care system, making health care decisions, and utilizing cancer screening, all contributing to disparities in cancer care. Health literacy is often a more powerful predictor of health disparities than more well-established predictors such as education and race/ethnicity. Moreover, individuals from traditionally medically underserved communities (e.g., racial/ethnic minority, low socioeconomic status [SES]) are at higher risk for lower health literacy, which can also reduce participation in cancer screening. This project will compare the intersections and differences between how Latina, Black, and non-Latina White women consider the benefits and harms associated with breast cancer screening mammography. The goal of this project is to create decision support tools for Latina, Black, and non-Latina White women with varying levels of health literacy under age 50 considering breast cancer screening mammography.