Disability Rights Commissioner Paula Tesoriero says she wants the Ministry of Health to confirm to her that it is not quietly reducing support for disabled people.
Faced with a $90m deficit for Disability Support Services (DSS), the ministry asked its needs assessors in February to come up with cost savings.
Proposed cost-saving measures - revealed in the Herald on Sunday - included limiting showers and meals and refusing help for autistic children, but they were dropped once ministers intervened.
"Those kinds of things would have a very negative impact on the lives of disabled people and I was obviously deeply concerned … that these ideas might have been pursued," Tesoriero said.
The commissioner was concerned that in the absence of wholesale funding cuts that regional needs assessment agencies (NASCs) were now making more subtle cuts on an individual basis.
"What people are telling me now is that despite no formal budgetary cuts, they are concerned that NASCs might feel under pressure to reduce spending and that therefore could affect the assessments and supports that people will have.
"I'd like an assurance from the ministry that the NASCs will receive a clear message that finding savings through reductions is not acceptable ahead of a formal review and increased funding."
The ministry's deputy director-general Adri Isbister said no changes were being made to funding packages "outside of normal process".
"People's packages have always been adjusted up or down as their needs change," he said.
However, providers have reported multiple instances this year in which people have had their support hours reduced - despite their assessors saying their hours should increase.
Isbister said demand for support had risen and this had placed extra pressure on the disabilities budget.
"It's really important to the Ministry and to each and every NASC that the services we deliver are delivered fairly and equitably to those who need them," he said.
Tesoriero wants further assurance from the ministry about a long-term funding model for the sector, following analysis by Deloitte's which showed it was underfunded by around $150 million.
After disability advocates raised concerns about possible reductions in support, she wrote to the Health Minister David Clark in early March. She received a response from Associate Health Minister Julie Anne Genter six weeks later, in mid-April.
In that letter, Genter told her that there had been no decision to cut disabled support. The minister also said the $1.2 billion disability budget had been maintained by taking money from elsewhere in the health budget.
"As you can imagine, this approach is not sustainable," Genter said.
The Government will reveal its first "wellbeing" Budget next month. While it has indicated that there will be more money for mental health services, it is not known whether the disabled sector will also get a boost.
Tesoriero said disabled people should be "front and centre" in the budget, and she would be disappointed if it did not include more money for Disability Support Services.
An additional $58m was put into Disability Support Services in last year's Budget.
Advocates said this had been swallowed up by regulatory and compliance costs - including wage increases required after the pay equity settlement for carers.
Disability Rights Commissioner Paula Tesoriero's letter to Health Minister David Clark:
Associate Health Minister Julie Anne Genter's response: