HBF collects almost half of Western Australia's private health insurance premiums

APRA's private health insurance performance data provides premium revenue for individual insurers across each state and territory.

Benchmark Analytics calculations show substantial differences in market concentration across Australia.

The standout among the larger states is Western Australia, where HBF accounts for 46.7% of private health insurance premium revenue. HBF is a Perth-founded, member-owned not-for-profit insurer established in 1941 and today has more than one million members nationally.

Bupa is WA's second-largest insurer and, together, the two largest providers account for 68.2% of premium revenue. The five largest collect 90.9%.

A useful measure of how these market shares combine is the Herfindahl-Hirschman Index, or HHI. It is calculated by squaring every insurer's percentage market share and adding the results. Because shares are squared, the measure deliberately gives much greater weight to large firms than small ones.

The ACCC considers markets with an HHI above 2,000 to be highly concentrated, although it emphasises that HHI depends on the definition of the relevant market and is not determinative by itself.

Western Australia's premium-revenue HHI is 2,852, compared with 1,607 nationally.

South Australia is also highly concentrated on this measure, recording an HHI of 2,616, with Bupa accounting for 45.5% of premiums. Queensland sits just above the 2,000 benchmark at 2,013. By comparison, NSW and Victoria record HHIs of around 1,710.

The figures do not establish that individual states constitute separate competition-law markets. But they reveal something the national figures conceal: the structure of private health insurance competition differs markedly across Australia, and in Western Australia one locally founded insurer remains extraordinarily dominant.

Source: Benchmark Analytics calculations from APRA Annual Private Health Insurance Performance Statistics 2024–25.