Trojan horse? The perils of a private health insurers' buying group for clinical independence, patient confidentiality, and the viability of private hospital care.

Private psychiatric care comprises outpatient as well as private hospital care. The three major funders of private hospital care in Australia are private health insurers, the Australian federal government and, through out-of-pocket costs not covered by the preceding, individual patients. Three big companies, Medibank, BUPA, and nib, dominate the private health insurance market in Australia, resulting in high returns on equity, while private hospitals are being progressively squeezed, resulting in falling profits and a loss in 2024-25. Nonetheless, private health insurers have sought increased collective bargaining power to negotiate fees with private hospitals and care providers, such as psychiatrists, through the formation of buying groups, which would further concentrate the market. In 2021, Honeysuckle Health and nib received authorisation from the Australian Competition and Consumer Commission to act as a buying group for private health insurers with a smaller market share, and other payers. However, a subsequent appeal revealed potential risks to patient and clinician autonomy from buying group contract conditions. In 2026, Honeysuckle Health has applied for an interim and ongoing authorisation from the ACCC to continue as a buying group. We discuss the context and implications of this application for private hospital care, including psychiatry.