People with disabilities would be "reduced to their impairment" if changes to the NDIS are approved, Australia's disability discrimination commissioner warns.
Laws before federal parliament seeking to overhaul parts of the disability scheme would require participants to carry out fresh assessments and receive a plan and budget based on their needs.
Money provided could then only be spent in accordance with their plan unless needs change significantly, with the government also able to create a list of services available as part of NDIS funding.
The overhaul came following a review of the scheme, which aimed to curb large levels of spending growth.
But disability discrimination commissioner Rosemary Kayess told a parliamentary inquiry examining the laws the changes would be a backwards step because of the assessments.
"What I perceive in the draft bill is a participant being reduced to their impairment, the consequence of which being that the NDIS support will be redirected towards their impairment and narrowly defined," she told a committee on Wednesday.
"This is a regression towards a medicalised approach to disability, focused on people with disability as recipients of welfare services."
Ms Kayess said the changes would mean the NDIS stood at odds with international human rights conventions on people with disabilities.
"NDIS supports need to be individually responsive, with plans developed in accordance with a person's needs, goals, aspirations and to facilitate social and economic participation," she said.
"This is the promise of the NDIS that is under threat with this bill."
The proposed laws follow a review, which recommended capping the scheme's growth to eight per cent per year.
The cost of the NDIS has been predicted to rise to $50 billion by 2025/26, higher than Medicare's annual cost.
People with Disability Australia president Marayke Jonkers said the assessments would only entrench one view of disability and not cater to specialised support.
"The current bill is beginning to look like it is homogenising people with disabilities because we can't specifically spit out a system that says 'everybody with a spinal cord injury needs X'," she told the inquiry.
"We need the funding to match that, to match the life that we want to live, and we need to so we can have our ordinary life."
Laura Henley from the Australian Federation of Disability Organisations said the NDIS changes had been rushed through without consultation with the disability community.
"Our concerns relate predominantly to .. the rushed nature and the lack of consultation and co-design surrounding the development of the bill, particularly given the lack of clarity of what foundational supports will exist outside the NDIS," she said.
"The government is yet to provide an official response to the recommendations arising out of the NDIS review."
NDIS Minister Bill Shorten said the changes needed to be implemented as soon as possible in order to make the scheme more sustainable.
