Health Minister Mark Butler will on Wednesday outline reforms to the $50 billion scheme, which are likely to include changes to who is eligible for support and tougher registration requirements for providers. Â
But as the government declared it would be negligent to allow NDIS expenditure to continue growing at about 10 per cent a year, people with disabilities and advocates have warned cuts to services would leave participants worse off.
Greens disability spokesman Jordon Steele-John said the community was worried the NDIS changes would not result in positive changes for those receiving support.
"Disabled people and their families are sick of being used as political footballs. We're in a situation right now where the state government is saying we cost too much," he told ABC Radio.
"People cannot understand ... why a government facing a budget, which is ultimately always about choices, would choose to cut their services."
People With Disability Australia president Jeramy Hope said the government needed to focus on making the scheme more efficient by reducing bureaucracy, rather than cutting eligibility to save money.
"Our community is scared and we want a surety that things are going to be OK," he told AAP.
The changes to the scheme come after it was announced in August children with autism would be moved off the NDIS and into a separate program called Thriving Kids.
That program will begin rolling out from October and be fully implemented by January 2028.
Senator Steele-John said conversations about the NDIS needed to focus on more than just financial stability.
"When the NDIS was set up, we didn't know how many disabled people there were. We do now, and there are more than were expected," he said.
"That means more people that need services and supports, the basic supports that they need to live. The NDIS is a net economic positive."
On Tuesday, Mr Butler and Treasurer Jim Chalmers briefed state and territory officials, who are reluctant to agree to any changes that would require them to pay more.
Martin Laverty, one of the architects of the NDIS, said the scheme was not designed to meet the needs of everyone with a disability.
"It was designed, sadly, for those with the most significant, permanent and profound disabilities, and because other disability programs ceased, the NDIS was overwhelmed," he told ABC Radio.
"Now it's the chance to reset and to establish evidence-based programs for people with mild to moderate disability outside of the NDIS itself."
National Disability Services chief executive Michael Perusco backed the government's push for change, warning the scheme had strayed far beyond its original purpose of supporting people with a lifelong, significant disability.
He also called for mandatory registration of all providers to make the scheme more transparent and accountable.
"At the moment, we've got the situation where only one out of 20 providers are registered. There isn't visibility of those other 19 providers, and that has to change," Mr Perusco said.
Aged Care Minister Sam Rae said the NDIS was designed to serve needs of those with profound disabilities and growth was being reduced to become more sustainable.
"We've got a commitment with the states and territories to further reduce growth to five to six per cent, to make sure that people living with disabilities can get the care that they need," he told ABC TV.