Abstract
In common with most high-income countries, the publicly funded healthcare system in Aotearoa New Zealand is struggling. The pressures of rising costs, an unstable workforce and changing population demographics appear intractable despite numerous system tweaks and reforms. This viewpoint article focusses on how resource constraints in New Zealand's public healthcare system have allowed the private health sector to grow and become the default provider of many non-urgent services and often also urgent or time-critical care, a process of "creeping privatisation". Increasingly, patients without the means to access care privately are significantly disadvantaged. Some ethicists have defended dual or "two-tier" health systems as permissible and preferable from the point of view of justice. We challenge this view, arguing that the New Zealand case shows how the private sector undermines and erodes the public sector, creating significant concerns for health equity, social solidarity and long-term sustainability. We examine a social insurance funding model for healthcare as a plausible alternative to the current tax-funded model used in New Zealand, with potential advantages in addressing the ethical challenges of a growing gap between the public and private "tiers".