Mutational signatures in breast cancer have been well-studied in populations of mostly Caucasian women. Our lab has shown that Black women are more likely to develop aggressive subtypes including basal-like and HER2-enriched tumors. While the expression data supports biological differences in tumors of Black and white women that lead to overall mortality differences, less is known about the role of mutational signatures in racial disparities. This preliminary examination in a targeted gene panel identified mutational signatures with high accuracy. Suggestive differences in frequency of signatures by race were noted. Ongoing sequencing will increase our sample size to further examine the factors that interact with mutational signatures leading to racial disparities.