Background: Oncology nurses working across the cancer continuum need communication tools in order to navigate between oncology and palliative care for the benefit of patients and their families. An evidence-based communication training course funded by the National Cancer Institute and identified by the acronym COMFORT was provided to 187 oncology nurses across the nation. Launched in 2015, it is the first train-the-trainer communication training course for nurses and addresses communication across the cancer continuum. Methods: The curriculum, emphasizing team communication, teaches nurses how to provide life-altering news, assess patient/family health literacy needs, practice mindful communication, acknowledge family caregivers, and address communication openings and goals. The curriculum covers the continuum of cancer care (diagnosis, treatment, survivorship, recurrence, end of life). Two courses were held and participants were contacted at six months for follow-up evaluation. Results: Course participants reported teaching an additional 2,460 healthcare providers, primarily nurses (1,961) and physicians (264). On average, each participant trained 21 nurses and two physicians. The training manual, which was provided during the course, was used by 81% of course participants and was rated as effective (7.71 out of 10). The most commonly taught curriculum modules were Communication (25.5%), Mindful Communication (22.3%), Team Communication (18.5%), and Family Caregivers (11.4%). Course participants reported that their institution were most effective with communication during treatment (7.21 out of 10) and least effective communication occurred during bereavement (5.02), at time of death (5.97), through survivorship (5.63), and with patients facing end of life (6.09). Conclusions: The train-the-trainer model for communication training appears to be a viable and promising strategy for broadly teaching communication across the cancer continuum. Train-the-trainer is less costly than traditional on-site training methods and allows instruction to be tailored to address the institution’s least effective communication practices across the cancer continuum.