Climate change necessitates urgent adaptation and mitigation, including in health systems. The World Health Organization co-launched the COP26 Health Programme as a platform for national commitments. Over 50 countries committed to environmentally sustainable and/or climate-resilient health systems. National health policies should reflect a contextual balance between mitigation and adaptation. These policies must recognize mitigation and adaptation interlinkages, combine bottom-up and top-down approaches and be based on evidence.