This operational framework, the related Vision for primary health care in the 21st Century, and associated technical documents are informed by reviews of the literature, regional reports prepared in 2018 on primary health care, country case studies on primary health care, a synthesis of lessons learned over the past 40 years, input from the International Advisory Group on Primary Health Care, and thematic reports on key issues relevant to primary health care. It builds on WHO’s work on primary health care over the past 40 years, notably the Global strategy for health for all by the year 2000, Primary Health Care 21: “Everybody’s business”, the Commission on Social Determinants of Health, the WHO Framework for Action for Strengthening Health Systems to Improve Health Outcomes, the World health report 2008: primary health care (now more than ever), and WHO’s framework on integrated, people-centred health services.