BACKGROUND At a population level, conversations between clinicians and seriously ill patients exploring patients' goals and values can drive high-value healthcare, improving patient outcomes and reducing spending. METHODS We examined the impact of a quality improvement intervention to drive better communication on total medical expenses in a high-risk care management program. We present our analysis of secondary expense outcomes from a prospective implementation trial of the Serious Illness Care Program, which includes clinician training, coaching, tools, and system interventions. We included patients who died between January 2014 and September 2016 who were selected for serious illness conversations, using the "Surprise Question," as part of implementation of the program in fourteen primary care clinics. RESULTS We evaluated 124 patients and observed no differences in total medical expenses between intervention and comparison clinic patients. When comparing patients in intervention clinics who did and did not have conversations, we observed lower average monthly expenses over the last 6 ($6297 vs. $8,876, p = 0.0363) and 3 months ($7263 vs. $11,406, p = 0.0237) of life for patients who had conversations. CONCLUSIONS Possible savings observed in this study are similar in magnitude to previous studies in advance care planning and specialty palliative care but occur earlier in the disease course and in the context of documented conversations and a comprehensive, interprofessional case management program. CONCLUSIONS Programs designed to drive more, earlier, and better serious illness communication hold the potential to reduce costs. METHODS Prospectively designed trial, non-randomized sample, analysis of secondary outcomes.