Australia's Home Support Algorithm: Why Assessors Lost Override Power
On 1 November, Australia's Support at Home classification algorithm took effect with no legal power for assessors or assessment delegates to override its recommendation under the Aged Care Rules 2025. The rule closed off human intervention at the point of classification. Department systems still contained a built override function, and assessors had been told they could use it. Guardian Australia
The mechanism sits inside the Integrated Assessment Tool, or IAT. Like a scoring sheet that produces a result, it starts with an interview. An assessor asks an older person about physical, social and personal circumstances. The algorithm then uses those answers to decide eligibility for government-funded home support. The IAT assists assessors in both home support and comprehensive assessments. Assessors open it through an app alongside the Australian National Aged Care Classification Assessment. The AN-ACC Assessment Tool is designed to identify the level of an older person's needs in residential aged care.
Internal emails released by the Department of Health, Disability and Ageing under freedom of information show how the no-override position was settled in the final days. On 24 October, assistant secretary Rachel Blackwood wrote to deputy secretary for aged care Greg Pugh about legal issues with letting assessors override the algorithm. On 26 October, Pugh replied that his chosen solution may not have been her preferred approach but was the best available in light of contextual circumstances.
Three days before rollout, ministers were briefed. Aged Care Minister Sam Rae and Health Minister Mark Butler received an emergency briefing on 29 October. Senior department staff warned in the 29 October email that there was a risk the late change in messaging on override powers might not filter through to assessor behaviour.
That risk followed a direct reversal. The department had previously told assessors, and said in public statements and media responses, that assessors would be able to override the classification algorithm recommendation. An override function had been built into the relevant systems. The function existed. The law did not allow it.
Days before rollout, the government barred aged care assessors from overriding the IAT. Documents described the IAT as having become a prescriptive tool that could no longer be overridden when assigning support. Guardian Australia
Departmental FOI release 26-3159 on the Single Assessment System sets out where discretion survived. Overrides are legally permitted for other aged care services, where the assessor overrides the IAT outcome to recommend a different outcome. For Support at Home, the scope is narrower. The Single Assessment System override option maps THCP to the equivalent dollar-value of Support at Home. The Support at Home override function does not allow a Support at Home classification at a lower dollar amount. Department FOI release
The Aged Care Assessment Manual was also revised. It removed guidance that instructed assessors to override the algorithm outcome to recommend TCP for clients who are new to the aged care system.
Operational pressure followed quickly. Assessors unable to override the algorithm-based tool left people at risk of being pushed into aged care homes before they were ready. Calls for help surged by 50% after the changes. Guardian Australia The assessment tool later became the centre of hundreds of complaints, with Labor resisting calls to change it in August 2026. Earlier, under Senate pressure, Labor had tweaked the algorithmic assessment tool to guarantee an extra layer of human oversight when determining the appropriate level of care. SMH
The broader context here is a familiar tension in automated eligibility systems between consistency and clinical judgment. A prescriptive classifier standardises decisions and limits variation across assessors. It also shifts decision-making from the assessor interview to the model design and the legal rule that gives that design force. When the Aged Care Rules 2025 removed discretion, the interview stayed human. The decision did not.
Looking at what this means for Single Assessment System governance, the difference between technical capability and legal authority will matter more than either alone. Override code can stay in systems while having no lawful use. Messages to frontline assessors can lag behind rule-drafting by days, and that lag shapes behaviour after go-live. For policymakers and providers, the questions that follow are operational. How exceptions are recorded when no lawful override exists, how THCP mapping and the bar on lower-dollar Support at Home classifications affect caseload mix, and how human oversight is defined when the classifier itself is prescriptive.
