A desire to enhance protection against health care costs and improve equity of access to health care lies at the core of many health sector financing initiatives. Until recently, international debates about financing and health equity have focused primarily on mechanisms to promote equity in relation to very specific elements of health systems. However, in recent years there has been growing interest in considering these equity challenges from a more systemic perspective. In this context, universal health coverage is becoming a rallying call, with a focus on how best universal coverage can be financed. This paper is the first in a special issue which presents a body of research whose overall aim was to critically evaluate existing inequities in health care financing and provision in Ghana, South Africa and Tanzania, and the extent to which health insurance mechanisms (broadly defined) could address financial protection and equity of access challenges. In this first paper we introduce the countries' health systems, with a special emphasis on existing mechanisms for financial protection. We also identify in broad terms the key challenges for universal coverage, setting the scene for the subsequent papers.