Abstract Universal health coverage (UHC) depends on a strong primary health-care system. To be successful, primary health care must be expanded at community and household levels as much of the world’s population still lacks access to health facilities for basic services. Abundant evidence shows that community-based interventions are effective for improving health-care utilization and outcomes when integrated with facility-based services. Community involvement is the cornerstone of local, equitable and integrated primary health care. Policies and actions to improve primary health care must regard community members as more than passive recipients of health care. Instead, they should be leaders with a substantive role in planning, decision-making, implementation and evaluation. Advancing the science of primary health care requires improved conceptual and analytical frameworks and research questions. Metrics used for evaluating primary health care and UHC largely focus on clinical health outcomes and the inputs and activities for achieving them. Little attention is paid to indicators of equitable coverage or measures of overall well-being, ownership, control or priority-setting, or to the extent to which communities have agency. In the future, communities must become more involved in evaluating the success of efforts to expand primary health care. Much of primary health care has taken place, and will continue to take place, outside health facilities. Involving community members in decisions about health priorities and in community-based service delivery is key to improving systems that promote access to care. Neither UHC nor the Health for All movement will be achieved without the substantial contribution of communities……article