Background: Clinical trials have demonstrated methods to minimize the risk of breast cancer-related lymphedema while preserving regional control. We sought to determine the percent lifetime-risk of breast cancer-related lymphedema that surgeons and radiation oncologists discuss with patients before axillary interventions. Methods: A nationwide survey of surgeons and radiation oncologists was performed from July to August 2020. Participants were asked to identify what number they discuss with patients when estimating the percent lifetime-risk of breast cancer-related lymphedema after different axillary interventions. Results: Six hundred and eighty surgeons and 324 radiation oncologists responded (14% response rate). While the estimated rate after sentinel lymph node biopsy was clinically similar between surgeons and radiation oncologists, statistically surgeons quoted a higher percent lifetime-risk (5.7% vs 5.0%, P = .03). Surgeons estimated significantly higher rates of breast cancer-related lymphedema compared with radiation oncologists (P < .001) for axillary lymph node dissection (21.8% vs 17.5%), sentinel lymph node biopsy with regional nodal irradiation (14.1% vs 11.2%), and axillary lymph node dissection with regional nodal irradiation (34.8% vs 26.2%). Conclusion: There is variability in the estimated rates of breast cancer-related lymphedema providers discuss with patients. These findings highlight the need for physician education on the current evidence of percent lifetime-risk of breast cancer-related lymphedema to provide patients with accurate estimates before axillary interventions.