Editor: Autism cases did not "skyrocket" in SA, the number of cases is completely inline with predictions. The SA Government and the NDIA ignored advice that the estimates they adopted were way too low. 

Disability South Australia is being forced to find up to $60 million in cuts, a state parliamentary committee has heard, with increased support only being offered for "must do" cases.

The Budget and Finance Committee was told that demand for services was outstripping funding increases and thousands more people were seeking cover under the National Disability Insurance Scheme (NDIS) than originally estimated.

Disability SA executive director David Caudrey said the number of children with autism seeking coverage had "skyrocketed".

"It is a considerable worry that the number of children with autism seems to be far, far more than was anticipated," he said.

He told the committee the Department for Communities and Social Inclusion had to find an extra $20.5 million in cuts annually for three years because of the blowout, with the majority of savings coming from his agency.

Mr Caudrey said decisions about services were based on what was merely enough to manage situations safely.

There'll be a range of services that will be reduced or not able to be provided in the general disability area to fund this blowout.

Disability SA executive director David Caudrey

He gave an example where a disability client living at home with their parents may have sought supported accommodation but was only offered an hour or two of home support instead.

"What we've got now is a situation where we only provide support for people if they are homeless or at risk of homelessness or if they're basically a risk through their challenging behaviours to themselves or their families," Mr Caudrey said.

"We like to think of it as really the 'must dos'. In other words, we've really cut back to emergency situations."

Mr Caudrey said it was creating inequities.

"When people came into the system, they might have come in at a time when we could do services of a particular type," he said.

"You come in at a later time when the budget is not as big ... and under those circumstances you don't get what someone might have got three years ago."

Wards temporarily shut to save money

Mr Caudrey said wards were sometimes shut at disability accommodation service Highgate Park, in Adelaide's inner south-east, to save money.

Some 50 departmental positions were also being cut.

"Basically, what we're doing, is not replacing people when they leave," Mr Caudrey said.

"We are basically asking whether every position is absolutely required."

Opposition Treasury spokesperson and committee chairman Rob Lucas said the State Government had been quiet on the extra cuts being sought.

"Clearly Treasury is requiring a $21.5 million a year cut for three years from disability services to help fund the blowout in the number of children in the National Disability Scheme.

"There'll be a range of services that will be reduced or not able to be provided in the general disability area to fund this blowout," he said.

Dignity for Disability MLC Kelly Vincent said it was vital young people with a disability were given the support they needed and were not punished for government funding miscalculations.

"It is not the fault of these children that the South Australian Government woefully underestimated the number of children who would be eligible for a NDIS plan," she said.

"It is on this Government's head, and the ball is very much in the Government's court, to find the funds to support these children."