Stephanie Maass was told her son Oliver needed occupational therapy and speech therapy when he was just 19 months old.

Key points: Stephanie Maass's family paid $4,000 for her son to receive private occupational and speech therapy to avoid the public system's waitlist

Stephanie Maass's family paid $4,000 for her son to receive private occupational and speech therapy to avoid the public system's waitlist Her son, Oliver, was diagnosed with autism and was eligible for funding through the NDIS

Her son, Oliver, was diagnosed with autism and was eligible for funding through the NDIS The NDIS rolled out in Tasmania in July, with 10,600 people identified as eligible

She tried to get that therapy through the public system in Hobart.

"They told us he would be on the waitlist for approximately a year, and that was just too long to wait for a child who needed help," Ms Maass said.

Ms Maass could not afford private therapy for Oliver, now four, but her parents and grandfather were able to help, paying about $4,000 over 18 months.

That led to Oliver receiving an autism diagnosis, meaning he was eligible for funding through the National Disability Insurance Scheme (NDIS).

Oliver Tsuha-Brown's family paid $4,000 for private therapy over 18 months. ( Supplied: Stephanie Maass )

The public disability support provider, St Giles, called back two years after the initial referral saying they had appointments available.

"We would've been waiting for two years for therapy," Ms Maass said.

"He wouldn't have been diagnosed yet, he would've gone without any sort of help at all if we didn't have financial backing from my family."

Gaps emerging as NDIS rolls out

The NDIS fully rolled out in Tasmania in July.

About 10,600 Tasmanians have been identified as eligible for the scheme and about 7,000 are participating so far.

St Giles chief executive Andrew Billing said the provider fully supported the NDIS and its intent, but it had created complexities.

"We're concerned about the speed of accessing services, particularly early intervention services for children, and we're concerned about us being able to move quickly enough to … provide the right supports at the right time, particularly for children," he said.

He said he had concerns about gaps emerging within the NDIS and state-funded public system for timely access to early intervention therapies for children with diagnosed disability, such as mild forms of cerebral palsy.

Mr Billing said an extreme shortage of allied health professionals, such as occupational therapists and speech therapists, was the main reason for long waitlists for children like Oliver.

"Waitlists have been common… [but] the move and transition to NDIS has challenged that even more," he said.

"We have a group of people with more choice and control over the services they're looking to access, and logically many of those families and participants are looking for more access to allied health supports."

Mr Billing said incentives had previously been used to draw health professionals to the state.

"I personally think we're in that environment at the moment where we need to be looking carefully at what incentives we can provide to bring allied health professionals into Tasmania, and their families," he said.

"Just recently we did some advertising overseas in places like Britain.

"We're looking at places like New Zealand, into some of the Asian countries as well, and we are looking for opportunities to bring allied health professionals from interstate and overseas."

Oliver Tsuha-Brown was diagnosed with autism, which made him eligible for funding through the NDIS. ( Supplied: Stephanie Maass )

State needs to do more: industry group

In 2015, about 131,000 Tasmanians identified as having a disability.

Will Kestin is the state manager of NDS Tasmania, the industry group that represents non-government disability service organisations.

He estimated while many of those people would be eligible for aged care supports, there were still about 80,000 people who were not covered by the NDIS or aged care.

Will Kestin from NDS Tasmania said about 80,000 people were not covered by the NDIS or aged care. ( ABC News: Ellen Coulter )

Mr Kestin said the state had clear responsibilities under its NDIS agreement with the Commonwealth.

"They're certainly meeting the minimal requirements of the bilateral agreement to date. Having said that, we have done a number of reports and studies about mainstream services and there are many, many gaps and many issues," he said.

Mr Kestin said as well as filling gaps in the workforce, the Government could do more to boost mainstream disability services that were part of the health, transport, education and justice systems.

Disability advocate David Cawthorn said some people who were not part of the NDIS found there was a perception they were "not disabled enough".

"There's still a gap that's got to be filled there. Just because they didn't make it into NDIS, that they're not going to be forgotten about," he said.

Upper House to look into issue

Tasmania's Upper House plans to look into the state's responsibilities regarding disability services next year.

Labor MLC Jo Siejka questioned whether the state was upholding its responsibilities for people who would never be eligible for NDIS.

"So much money and [so many] resources go into the NDIS," Ms Siejka said.

"We need to make sure that the other side, the vast majority of people living with disabilities in Tasmania, have their needs met

In a statement, Tasmanian's Minister for Disability Services Roger Jaensch said Tasmania was meeting its obligations under the NDIS.

"There is a nationally recognised shortage of allied health professionals to meet demand and Tasmania is working with the Commonwealth on a range of workforce-focused activity, including the training, attraction and retention of allied health professionals," he said.

He said the State Government also provided funding for free autism diagnosis.

The state allocates about $3.3 million, plus GST, to St Giles each year to deliver mainstream, early childhood intervention.

In a statement, an NDIS spokesman said the Department of Social Services and the NDIA (National Disability Insurance Agency) were working together to better ensure NDIS participants had access to the supports they required.

"The NDIS is designed to complement, not replace, services that states and territories provide," the statement said.

An inquiry would be welcome news for Ms Maass, whose youngest child Zoe is now trying to get therapy through the public system.

"You want your children to get early intervention and the help that they actually need and you're just hitting red tape and brick walls constantly," she said.