Background: Risk of breast cancer recurrence can be estimated with tools such as Adjuvant! Online, but little is known about how medical oncologists and surgeons use such tools or communicate risk information to patients. Methods: In 2012, we surveyed 750 medical oncologists and 750 surgeons identified using the AMA Physician Masterfile (a comprehensive physician list not limited to AMA members). Using a vignette, we evaluated risk communication practices (discussing risk using descriptive words, discussing risk using numbers, using online calculators, providing copy of risk estimates) and analyzed correlates of specific approaches in a logistic regression model that included physician (e.g., gender, specialty) and practice characteristics (number of breast cancer patients seen in past year, multidisciplinarity [i..e., offering same-day multi-specialty appointments]). Results: 498 surgeons and 398 medical oncologists responded (60.5% response rate). We excluded 130 who did not see breast cancer pts. Respondents averaged 19 years in practice, 79% were male, 74% saw > 10 breast cancer pts/yr, and 45% offered same-day multi-specialty appointments. 84% of medical oncologists and 85% of surgeons reported discussing recurrence risk using terms such as “high risk.” Medical oncologists were much more likely than surgeons to use an online risk calculator (76 vs 24%, p < .001), provide numerical risk estimates (88 vs 47%, p < .001), and provide a copy of risk estimates (71 vs 17%, p < .001). Specialty (p < .01) and multidisciplinarity (p < .01) were the only significant independent correlates of communication practices. After controlling for specialty, clinicians offering same-day multi-specialty appointments were more likely to use online calculators (OR 1.6, 95% CI 1.1 - 2.3) and discuss numerical risk estimates (OR 1.8, 95% CI 1.2 - 2.5). Conclusions: Most medical oncologists use online calculators and numerical estimates to communicate recurrence risk to breast cancer patients; fewer surgeons do so. Patients who do not see a medical oncologist until after surgery may make critical treatment decisions (including whether to remove the contralateral breast) without full understanding of relevant risk information.