One public college and 18 public schools will have a significant cut in their funding in a change to the formula for school funding for 2027.
College principals were briefed on Monday ahead of the release of budgets on Tuesday that the per student weighting given to colleges would be reduced next year.
An additional $40.5 million will be directed towards support for students with a disability, specialist schools and students with complex behaviours.
Education Directorate director-general Jo Wood said the ACT public school system resourcing review showed that primary schools and early childhood schools were under greater budget pressures and resources should be redistributed to be more equitable.
"Overall as a system we're sustaining resourcing and in fact the budget for '26-'27 was an increase of 7.3 per cent on our budget from the previous financial year," Ms Wood said.
"But we are seeking to redistribute that funding and how that funding is used in the system, and that is responding to what the public school system resourcing review recommended.
"It said we needed to redistribute with a focus on equity and student need."
Ms Wood said in a normal year school budgets could fluctuate by plus or minus 5 per cent because of changes in enrolments and student demographics.
As part of the new distribution of funding, some schools will have increases or decreases outside this 5 per cent threshold.
For the public colleges:
For the rest of the ACT public school system:
Schools get a weighting per student depending on their stage of schooling: primary, high school or college.
Ms Wood said the directorate was commissioning a full review of the funding formula for schools but was making a step towards greater equity in 2027 with an adjustment to the weighting for colleges.
Australian Education Union ACT branch president Angela Burroughs said one college principal warned they may have to cut a whole subject program to find savings.
"Certainly some of the variations that we were hearing about [on Monday] are large and you know you can't just trim a bit here and a little bit there, and particularly in a really short time frame," Ms Burroughs said.
"It's disingenuous to say that there will be some colleges that actually get a budget increase because it's for a different reason. It's because... they're projected to have more students with more complex needs that attract certain loadings."
Ms Wood said schools would have to examine staffing levels, timetabling and subject offerings to meet the new budgets.
"The really important thing where there's larger decreases is we do recognise that this is a transition we need to support schools through," she said.
"So we do have a central funding pool as well to work with schools on how they can make reductions, and where we find that it's actually not possible to make that larger reduction."
The Education Directorate is moving away from a model of disability funding based on a student's diagnosis towards a model based on the adjustments they need in the classroom, as captured by the Nationally Consistent Collection of Data on students with disability (NCCD).
Ms Wood said more students would qualify for extra funding based on disability and the directorate was working with principals on the best way to use this funding.
She acknowledged budgeting was a stressful subject for principals but most were supportive of the system-wide reforms.
"I'm not at all suggesting it's not stressful, and it is, but broadly and absolutely, the majority of principals give me positive feedback about the steps we're trying to take towards one-public education system."
