Background: Several clinician training interventions that address serious illness communication have been developed over the past decade. While numerous studies report the impact on clinician attitude, confidence and intention to change practice, less is reported on individual education modalities and their impact on actual behavior change and patient outcomes. This study's aim was to examine what is known about the education modalities used in serious illness communication training and their impact on clinician behaviors and patient outcomes. Methods: A scoping review using the Joanna Briggs Methods Manual for Scoping Reviews was conducted of studies that specifically measured clinician behaviors or patient outcomes. Ovid MEDLINE and EMBASE databases were searched for English-language studies published between January 2011, and November 2021. Results: The search identified 1132 articles: 60 met inclusion criteria describing 49 unique interventions. Common education modalities used were a single workshop (n = 18), multiple workshops (n = 8), single workshop with coaching (n = 7), multiple workshops with coaching (n = 5); though they were inconsistently structured. Studies reporting improved clinician skills tended to be in simulation settings with neither clinical practice nor patient outcomes explored. While studies reporting behavior changes or improved patient outcomes did not confirm improvements in skills. As multiple modalities were commonly used and often embedded within larger quality improvement initiatives, the impact of individual modalities could not be determined. Conclusions: To advance the evidence of the benefits of serious illness communication training, well-defined education modalities and consistent outcome measures for behavior change and patient outcomes are needed.