Poor health behaviors (e.g., smoking, poor diet, and physical inactivity) are major risk factors for noncommunicable chronic diseases (NCDs). Evidence supporting traditional advice-giving approaches to promote behavior change is weak or short lived. Training physicians to improve their behavior change counseling/communication skills is important, yet the evidence for the efficacy and acceptability of existing training programs is lacking and there is little consensus on the core competencies that physicians should master in the context of NCD management. The purpose of this study is to generate an acceptable, evidence-based, stakeholder-informed list of the core communication competencies that physicians should master in the context of NCD management. Using a modified Delphi process for consensus achievement, international behavior change experts, physicians, and allied health care professionals completed four phases of research, including eight rounds of online surveys and in-person meetings over 2 years (n = 13–17 participated in Phases I, III, and IV and n = 39–46 in Phase II). Eleven core communication competencies were identified: reflective listening, expressing empathy, demonstrating acceptance, tolerance, and respect, responding to resistance, (not) negatively judging or blaming, (not) expressing hostility or impatience, eliciting “change-talk”/evocation, (not) being argumentative or confrontational, setting goals, being collaborative, and providing information neutrally. These competencies were used to define a unified approach for conducting behavior change counseling in medical settings: Motivational Communication. The results may be used to inform and standardize physician training in behavior change counseling and communication skills to reduce morbidity and mortality related to poor health behaviors in the context of NCD prevention and management.