Background: Communication between clinicians and patients fundamentally shapes the experience of serious illness. There is increasing recognition that health systems should routinely implement structures and processes to assure high-quality serious illness communication (SIC) and measure the effectiveness of their efforts on key outcomes. The absence, underdevelopment, or limited applicability of quality measures related specifically to SIC, and their limited application only to those seen by specialist palliative and hospice care teams, hinder efforts to improve care planning, service delivery, and health outcomes for all seriously ill patients. Objective: We convened an expert stakeholder symposium and subsequently surveyed participants to consider challenges, opportunities, priorities, and strategies to improve quality measurement specific to SIC. Results: We identified several barriers and opportunities to improving quality measurement of SIC. These include issues related to the definition of SIC, methodological challenges related to measuring SIC and related outcomes, underutilization of technologies that can facilitate measurement, and measurement development, and dissemination. Conclusions: Patients, clinicians, and health systems increasingly align around the importance of highquality communication in serious illness. We offer recommendations for various stakeholder groups to advance SIC quality measurement. Enthusiasm and a sense of urgency among health systems to drive and measure communication improvements inform our proposal for a set of example measures for implementation now.