Children who already receive disability loading will continue to receive the same loading as last year, but with a 4.5 per cent indexation.

Those children with disability who miss out on the loading because their IQ does not fall into the support bracket will continue to miss out on support.

Australian Education Union state president Terry Polglase said the budget offered no hope and zero vision, with Tasmania losing $136 million from the ignored additional years of Gonski funding reforms.

Tasmanian Disability Education Reform Lobby founder Kristen Desmond said she could see no additional money for students with disability allocated in the federal budget, apart from the increased indexation.

"It has a particular impact on Tasmania because we are very much IQ based," Ms Desmond said.

"There are kids who desperately need support, and schools are stretching their resource budgets for support, but the reality is there is no extra funding.

"A lot of schools are already struggling to provide support to students who aren't on the disability register or who don't have IQ under 55."

Education Minister Christopher Pyne said the budget offered students with disability extra support worth $1.3 billion in 2015-16, and more than $5 billion up until 2017 through disability loading.

"From 2016, for the first time ever, Commonwealth funding will be informed by the National Consistent Collection of Data on School Students with Disability (NCCD) so that all students with disability are funded on the same basis, regardless of the state or territory in which they live," he said.

But Ms Desmond said his words were ambiguous.

"Does he mean those NCCD numbers will inform next year's funding and, if that is the case, I don't believe there has been enough allocated in the budget," she said.

"The NCCD are important because they were meant to inform a needs-based specific disability loading to each student no matter where they were in the country."