Several recent studies have investigated the validity of precautionary practices for lymphedema risk reduction after breast cancer treatment, such as avoidance of blood pressure measurements, skin puncture, blood draws, and use of prophylactic compression during air travel. Other studies have elucidated risk factors for breast cancer-related lymphedema, such as axillary lymph node dissection and skin infection (cellulitis). Combining the current evidence base with the consensus opinion of lymphatic experts assembled at the American Cancer Society/Lymphology Association of North America Summit in October 2023, updated evidence-based risk reduction recommendations are presented for those with or at risk of breast cancer-related lymphedema. Recommendation topics include prospective surveillance, patient education, individual risk factors, exercise, blood pressure, skin care and hygiene, skin puncture and blood draws, surgical procedures, prophylactic compression, air travel, and hot climate and sauna. These recommendations will help inform education and medical choices for individuals treated for breast cancer who are at risk of or diagnosed with breast cancer-related lymphedema. More high-quality evidence is required to allow the development of risk reduction recommendations for other cancer types such as gynecological, melanoma, and head and neck. It is recommended that clinicians and organizations serving people at risk of or with lymphedema align risk reduction guidelines with the evidence-based recommendations provided within this consensus document and companion manuscripts from the American Cancer Society/Lymphology Association of North America Lymphedema Summit: Forward Momentum: Future Steps in Lymphedema Management.