Private health insurance has offered a primary source of coverage for population groups ineligible to public programmes, and contributed to provide insurance protection against other public system coverage gaps. It has helped to inject resources into health systems, enabling an expansion in capacity and services. It also enhanced access to timely care in some systems experiencing prolonged public sector waiting times. However, all of these advantages have depended upon the structure and regulation of delivery systems, insurers’ strategic behaviours, the role that PHI plays, and regulation of public and private coverage. Furthermore, clear trade-offs have emerged. When resources and supply are scarce, it may be efficient to.