We have read two quarters of the Star Ratings workbook on this site and reached the same conclusion both times: the overall number tells you very little, and the variation is in the sub-ratings. That is a finding about the data. This is the mechanism behind it, taken from the department’s own manual rather than inferred, and it is worth knowing before you compare two homes.
Four ratings, four different weights
The overall rating is built from four sub-categories, and they do not count equally. The
manual publishes the weights and, unusually, publishes the working behind them. Each
sub-category was scored twice: once for priority, meaning relative importance, and once for
data maturity. each measure was given a score out of 100 for importance and a score out
of 100 for maturity
, and These scores were combined to determine the size of its
contribution to the Overall Star Rating
.
Star Ratings weighting, as published in the Star Ratings Provider Manual
| Sub-category | Priority | Data maturity | Total | Weight |
|---|---|---|---|---|
| Residents’ Experience | 100 | 70 | 170 | 33% |
| Compliance | 67 | 90 | 157 | 30% |
| Staffing | 67 | 50 | 117 | 22% |
| Quality Measures | 67 | 10 | 77 | 15% |
| Total | 521 | 100% |
The clinical measures count least, and importance is not the reason
Read the priority column on its own and three of the four sub-categories are scored identically: Compliance, Staffing and Quality Measures all sit at 67, behind Residents’ Experience at 100. On importance, in other words, the department rates clinical outcomes exactly level with regulatory compliance and staffing.
The gap opens entirely in the second column. Quality Measures scores 10 out of
100 for data maturity, against 90 for Compliance, 70 for Residents’
Experience and 50 for Staffing. That single number is what drops it to the smallest weight
of the four. The manual describes the exercise plainly: To determine data maturity,
experts assessed the Star Ratings data and considered how it should be weighted based on
potential improvements in collection and reporting over time.
The stated basis for the
weighting is the quality and maturity of the data was also considered when determining
the weighting of each sub-category
.
This is a defensible design and it is also a real limitation, and both should be said. It
is defensible because a rating built on immature data would mislead in a different and
worse way. The limitation is that the five clinical indicators the program collects,
pressure injuries, restrictive practices, unplanned weight loss, falls and major injury, and
medication management, are the outcomes most families think they are reading when they look
at a star, and they are the quarter of the score that moves it least. The manual also notes
the clinical data is adjusted before use, so that Quality indicator data is transformed
and adjusted when calculating the Quality Measures rating to account for differing levels of
care need across aged care homes, to allow for fair comparison
.
Why so many homes land on exactly four stars
The weighted calculation produces a decimal, and the decimal is then rounded:
The Overall Star Rating is a single whole number from 1 to 5. No half stars or decimals
are included.
The bands are wide. A score of 3.50-4.49 results in an Overall Star
Rating of 4 stars
, which is a full point of range collapsed into one published number.
That is the arithmetic behind the finding we published in July, that 71.9 per cent of rated homes held exactly 4 stars while more than a quarter scored 1 or 2 on Staffing. A home can be a long way from another home and print the same star.
Our own worked example, using the published weights: a home rating 5 on Residents’ Experience, 5 on Compliance and 5 on Quality Measures, but 1 on Staffing, scores 4.12. That is inside the 3.50 to 4.49 band, so it publishes as a 4-star home. Staffing is 22 per cent of the score, and one point of range is enough to absorb it.
The one sub-rating that overrides the others
There is a single exception to the weighting, and it runs the other way. Compliance can
veto everything else: An aged care home that receives a 1 star Compliance rating will
receive a 1 star Overall Star Rating regardless of how they perform in other
sub-categories.
And a step up from that,
Aged care homes that receive a 2 star Compliance rating cannot receive an Overall Star
Rating higher than 2 stars regardless of how they perform in other sub-categories.
So a 1 or 2 star overall rating is not a weak average. It is a regulatory finding showing through, and it means something quite different from a 3.
What to read instead
Three things, in this order. Compliance first, because it is the one that
caps everything and it is the closest thing to a regulator’s current opinion of the
home. Then the sub-rating that matches what you are worried about: staffing
if it is care minutes, Quality Measures if it is falls or pressure injuries, whatever the
overall star says. Then the Residents’ Experience detail, which
carries the largest weight and is the only part sourced from residents themselves. It is a
face-to-face annual survey where A minimum of 20% of residents living in each
participating aged care home are surveyed each year.
and, worth knowing,
Providers are not involved in the selection of residents.
The overall star is a reasonable first filter and a poor last word. Our reading of the August quarter found the same thing from the other direction: when 235 homes gained a staffing rating for the first time, four in five of them landed on 1 or 2 stars, and the sector-wide average moved without any home getting worse.
How we made this. Read on 24 August 2026 from the Star Ratings Provider Manual published by the Department of Health, Disability and Ageing, and from the department’s own How Star Ratings works page. Every passage in quotation marks is verbatim from the manual.
We checked the published percentages rather than repeating them. The manual gives both the inputs and the outputs, so the arithmetic can be reproduced: the four totals of 170, 157, 117 and 77 sum to the manual’s stated 521, and dividing each by 521 gives 32.6, 30.1, 22.5 and 14.8 per cent, which are the published 33, 30, 22 and 15 to the nearest whole number. That is the check, and it also confirms the table was read down the right columns, which is the way a figure taken from a PDF most often goes wrong.
The 4.12 worked example is our own calculation on the published weights, not a case from the data: 5 × 0.33, plus 5 × 0.30, plus 1 × 0.22, plus 5 × 0.15. The 71.9 per cent and the 235-home figures come from our own earlier analysis of the May and August quarterly extracts, which are linked in those pieces.
A note on scope. This describes the calculation, not whether the ratings are a good measure of care, which is a larger question and not one a methodology document can settle. We hold no interest in any provider, and this is general information rather than advice about a particular home.
Sources
- Star Ratings Provider Manual, Department of Health, Disability and Ageing (read 24 August 2026): the weighting table and its priority and data-maturity inputs; that each measure was scored out of 100 for importance and for maturity and the scores combined; the description of how data maturity was determined; that the overall rating is a whole number from 1 to 5 with no half stars; the rounding bands including 3.50 to 4.49 for 4 stars; the compliance rules capping the overall rating at 1 and 2 stars; the risk adjustment applied to quality indicator data; the five quality indicators; and the Residents’ Experience survey details including the 20 per cent minimum and that providers are not involved in selecting residents.
- Department of Health, Disability and Ageing, How Star Ratings works (read 24 August 2026): the four sub-categories and the department’s public description of the rating.
Spotted an error? The correction form is on our tips page; we check every correction against the cited sources and log the outcome here.