In order to address the health care system’s environmental footprint, which is 8.5 percent of all carbon emissions in the United States, and prepare for extreme weather events that can disrupt care, health systems are increasingly hiring chief sustainability officers to develop and implement sustainability strategies. Success in these roles is contingent on securing buy-in from a diverse set of stakeholders with competing priorities and demands on their time and resources, including organizational leadership, frontline staff, and facilities managers. The Guide to Communicating Sustainability provides helpful tips and resources for health system sustainability leaders. This guide contains best practices in sustainability communication, advice on how to talk to key audiences in your health system, and a list of helpful resources you can consult for more details to ultimately maximize the impact and cost savings of sustainability initiatives and building a health system’s resilience to climate impacts.