BRCA1 and breast cancer: In this population‐based study of Massachusetts women aged 45 years and under with breast cancer, we found that non‐Hispanic Black women, Medicaid‐insured women, and women living in lower‐income areas were statistically less likely than White, privately insured women, and women living in higher‐income areas, respectively, to receive guideline‐concordant BRCA1/2 testing within 6 months of diagnosis, adjusting for other factors.