Autism groups have expressed shock and disappointment at reports the agency administering the National Disability Insurance Scheme is looking to cut the number of autistic people who are virtually guaranteed of qualifying for support.

Advocates said they believed the National Disability Insurance Agency was working on plans to rein in costs by changing the qualification criteria so that many people would have to be individually assessed to determine their need for support.

The Australian reported on Saturday that the secret plan meant people with the second-most severe of the three recognised categories of autism would no longer be placed on so-called “List A”, which virtually guarantees help under the scheme.

The agency published part of its new plan last week but swiftly removed it and apologised, saying it was a mistake.

Nicole Rogerson, chief executive officer of Autism Awareness Australia, said the government appeared to be backing away from “the commitment to properly fund kids with disabilities” for simple cost-cutting reasons.