More than 200 NDIS participants were having their funding slashed by 20 per cent or more every day in the final months of the Morrison government, internal documents have revealed.
But almost double the number of plans increased substantially in the same period, according to the agency in charge of the scheme.
A leading disability advocate described the number of participants suffering deep budget cuts as "unimaginable" as she called for answers on when they started and how they became so prevalent.
Reports of NDIS plans being cut exploded in the past 12 months, prompting a surge in appeals to the Administrative Appeals Tribunal and turning the scheme into a hot-button political issue in the lead up to the federal election.
The former Coalition government repeatedly rejected suggestions of mass cuts, pointing to the ballooning overall cost of the now nearly $30 billion-a-year scheme.
Labor went to the May 21 poll vowing to "defend" the NDIS and stop what it described as "unfair" cuts to participants' funding.
It promised to introduce a new system under which decisions to cut a participants' annual funding by 20 per cent or more would be sent for an expert review.
The incoming government brief prepared for new NDIS Minister Bill Shorten reveals just how many plans were being slashed to that degree, and therefore would have been subject to an expert review had Labor's system been in place under the former regime.
Based on "current experience" about 4500 plans per month - or 225 per weekday - would be sent for expert review, department officials told Mr Shorten in a brief obtained by The Canberra Times under freedom of information.
A National Disability Insurance Agency spokeswoman confirmed the figures, which she said related to the nine months to March 31.
The spokeswoman added that about 8000 plans per month increased 20 per cent or more over the period.
"Plan values may fluctuate depending on a range of factors, including one-off capital items, changes to a participant's needs or goals, or the investment in capacity building resulting in less need for core support over time," the spokeswoman said.
The Canberra Times has contacted Mr Shorten's office, seeking an update on its progress implementing the expert review system.
They flagged the reviews could increase the NDIA's workload, saying "staffing implications" of the process would need to be considered in "settling the overall agency resourcing".
People with Disability Australia president Samantha Connor said the figures revealed in the briefing confirmed that participants had been "short changed".
"In the middle of a global pandemic, it's an unimaginable number of people who are being let down by a scheme supposed to help people," she said.
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