NDIS evidence requirements for an autism diagnosis

Adult Autism Assessment Perth arranges autism and ADHD assessments for adults and adolescents across Perth and WA. Here is what the scheme actually asks for.

Diagnosis and functional impact are two different things

This is the distinction that costs people the most time. The NDIS does not fund people because of a label. It funds people whose disability causes substantially reduced functional capacity in defined areas.

So an access request generally needs two things:

1. Evidence of the diagnosis — a report from a qualified professional stating the diagnosis and how it was reached.
2. Evidence of functional impact — what you can and cannot do day to day, in specific terms, across the domains the scheme assesses.

A diagnostic report frequently covers the first thoroughly and the second barely at all, because it was written to answer a different question.

The six domains

Functional capacity is assessed across:

• Communication — being understood, understanding others, managing phone calls, correspondence and appointments
• Social interaction — forming and maintaining relationships, coping in groups, managing conflict
• Learning — acquiring and applying new skills, following instruction
• Mobility — moving around, including using transport
• Self-care — daily living, personal care, health management
• Self-management — planning, organising, decision-making, managing money and appointments

Autistic adults are most often substantially affected in communication, social interaction and self-management. Executive function difficulty sits in the last of those and is regularly the strongest part of an application.

What a functional capacity report adds

It translates the diagnosis into evidence the scheme can act on, using standardised measures rather than description alone. Commonly that includes the Adaptive Behaviour Assessment System, which scores everyday functioning against population norms and produces the kind of figure an assessor can weigh.

It also documents what happens without support, which is the part applicants most often under-state — people describe their best day, because that is the version they are used to presenting.

Write about your worst week, not your best day

The most common reason a genuine application fails is understatement. Autistic adults are frequently practised at coping and at minimising, and an assessor reading "I manage most of the time" has been told the application is not needed.

Describe what happens when you are not managing. Be specific. "I did not open mail for six weeks and a debt went to collections" is evidence. "I struggle with admin" is not.

The order that works

1. Get the diagnosis. The NDIS does not fund the diagnostic assessment that establishes eligibility — see Medicare and rebates.
2. Decide whether you are applying. A diagnosis has value regardless; not every autistic adult needs or seeks NDIS support.
3. If you are, get functional capacity evidence written for that purpose, rather than hoping the diagnostic report covers it.
4. Submit both together.

Tell us at the enquiry stage if the NDIS is your reason, so the assessment is scoped to answer it and you are not paying twice.

What we charge for it

NDIS report preparation is $590, quoted separately from the diagnostic assessment because it is separate work. Indicative and confirmed in writing before anything is booked.

If access is refused

A refusal is not the end. You can request an internal review, and after that go to the Administrative Review Tribunal. Refusals are frequently about insufficient functional evidence rather than a judgement that you are not disabled — which means better evidence, not a different diagnosis, is usually what changes the outcome.

Sources

Access requirements and the evidence the scheme asks for are published by the NDIS. Australian diagnostic standards are set out in the National Guideline for the Assessment and Diagnosis of Autism in Australia.