NDIS “Reasonable and Necessary” (NDIS Act s 34): Plain-English Guide

NDIS AT Knowledge Base / Eligibility & Law / Reasonable & Necessary (s 34)

Published March 2026  ·  NDIS AT Explained Series  ·  LowCost AT

This guide explains the NDIS Act s 34 “reasonable and necessary” test in plain English — what each criterion means, what evidence helps, and the most common reasons AT requests are refused.

In brief — s 34

The NDIA can only fund Assistive Technology (AT) if it meets the “reasonable and necessary” criteria in s 34 of the NDIS Act. In practice, refusals usually turn on disability link (s 34(1)(aa)), value for money, and whether another system should fund the support. This guide breaks down each criterion and the evidence that usually strengthens an AT request.

1. What is “reasonable and necessary” under the NDIS?

“Reasonable and necessary” is the statutory gateway for all NDIS funding. Section 34(1) of the National Disability Insurance Scheme Act 2013 (Cth) sets out six criteria the CEO of the NDIA must be satisfied the support meets before it can be included in a participant’s plan.

The test applies to every AT item regardless of cost. A $30 continence aid must satisfy s 34(1) just as a $30,000 wheelchair must. The difference is the evidence required — the NDIA’s own operational guidelines apply a lighter documentation touch to lower-cost items, but the statutory standard is the same.

The six criteria at a glance
s 34(1)(a) Effective and beneficial — having regard to currently available good practice
s 34(1)(aa) ★ Necessary to address needs arising from the s 24/25 impairment — the most commonly refused criterion for AT
s 34(1)(b) Value for money relative to benefits and cost of alternatives
s 34(1)(c) Appropriate for the participant, having regard to the NDIA’s assessment of their needs
s 34(1)(d) Takes into account what is reasonable to expect of informal supports (family, community)
s 34(1)(e) Most appropriately funded through the NDIS — not through health, education or other systems

★ s 34(1)(aa) was inserted by the National Disability Insurance Scheme Amendment (Getting the NDIS Back on Track No. 1) Act 2024 and is the criterion most frequently at issue in AT funding disputes.

2. s 34(1)(aa): Disability link — “arising from” the impairment

Section 34(1)(aa) requires that the support be necessary to address the needs of the participant arising from their qualifying disability or condition (the s 24 or s 25 impairment on the basis of which they gained NDIS access).

This is the provision the NDIA has most often used to refuse AT — arguing that a participant’s need arises from:

Common NDIA argument 1 The need arises from a condition that is not the qualifying s 24 impairment (e.g. from a physical condition rather than the vision impairment that gave access)
Common NDIA argument 2 The need arises from environmental factors (e.g. regional location, absence of public transport) rather than from the disability itself
Common NDIA argument 3 The AT item resembles a consumer product or mainstream item that anyone could buy — therefore not disability-specific

All three of these arguments were considered by the Federal Court in Eastham. All three were rejected.

3. How Eastham [2026] FCA 147 affects s 34(1)(aa) — contributory cause

In CEO of NDIA v Eastham [2026] FCA 147, Justice Wheelahan of the Federal Court dismissed the NDIA’s appeal and confirmed the correct interpretation of s 34(1)(aa). This is the most significant NDIS AT decision since the Act commenced.

Para 83 Contributory causation is sufficient

The s 24 impairment does not need to be the sole or dominant cause of the need. It is sufficient that it be a genuine contributory cause. The phrase “arising from” in s 34(1)(aa) is satisfied where the qualifying impairment meaningfully contributes to the need, even if other factors also contribute.

Para 88 Applied to Ms Eastham’s facts

Ms Eastham’s vision impairment (the s 24 impairment) prevented her from holding a driver’s licence and operating a motor vehicle. This was a direct and genuine cause of her need for funded transport. The co-existence of physical impairments affecting her mobility did not displace this causal connection.

Note (b) Environmental factors are part of the factual matrix

Note (b) to s 34(1)(aa) expressly recognises that a support need may be affected by environmental factors (transport availability, terrain, distance, service hours) and by impairments that do not themselves satisfy s 24. These factors do not disqualify a claim. They are part of the factual context in which the disability-related need exists.

Paras 106–115 Schedule items: inherent design, not use

Items in the NDIS Schedule of Supports are characterised by their inherent design, not by how a participant uses them or where they can also be purchased commercially. A modified vehicle does not become a consumer product merely because unmodified vehicles are available for retail purchase.

What Eastham means for your AT documentation right now

Before Eastham: Practitioners often softened or omitted references to non-s 24 conditions to avoid NDIA scrutiny. This created credibility problems on review.

After Eastham: Name the s 24 impairment. Acknowledge all other conditions. Show how they interact with the s 24 need. Note (b) is your authority for including the full picture. Hiding complexity weakens the claim.

4. s 34(1)(b): Value for money — how to evidence it

Value for money under s 34(1)(b) is assessed relative to two things: the benefits achieved and the cost of alternative supports. It is not a cheapest-option test. An expensive AT item can represent better value for money than ongoing support worker hours performing the same function.

The evidence that most reliably demonstrates value for money:

Evidence type Why it helps
Comparison to support worker hours If the AT replaces 3 hours of support worker time per week, calculate the annual cost differential against the AT purchase price. A one-off AT cost often wins on a 2–3 year horizon.
Alternative AT options considered Name the lower-cost alternatives that were trialled or assessed. State why each was inadequate for this participant’s specific functional profile. This satisfies value for money and alternatives (s 34(1)(d)).
Functional benefit quantified Where possible, express benefit in measurable terms: independence in X tasks per week, reduction in support hours, safety incidents prevented. Qualitative benefit statements alone are weaker.
Quotes from registered suppliers Two or three quotes demonstrate the price is market-competitive and makes NDIA challenges to cost harder to sustain.

5. s 34(1)(a): Effective and beneficial — what good evidence looks like

The support must be likely to be effective and beneficial for the participant, having regard to currently available good practice. This is individualised — population-level evidence supports but does not substitute for participant-specific rationale.

The three levels of evidence, from strongest to weakest:

1
Trial outcomes with this participant The AT was trialled with this participant and the report documents observed outcomes, task performance, participant preference and any safety considerations. This is the gold standard and hardest for the NDIA to dispute.
2
Clinical assessment + published good practice The practitioner’s clinical assessment links this participant’s specific functional profile to published evidence or recognised clinical standards (e.g. CAOT, AAC guidelines, O&M standards). Name the guideline. Quote the relevant recommendation.
3
Professional opinion alone Professional judgement without trial or referenced standards is the weakest form of s 34(1)(a) evidence. It can be sufficient for low-risk, well-established AT but is vulnerable for novel, high-cost or disputed items. Upgrade to level 1 or 2 where possible.

6. s 34(1)(d)–(f): Informal supports & mainstream responsibility

These three criteria are often overlooked in AT documentation but together account for a significant proportion of refusals, particularly for:

Items that carers could assist with Hospital discharge AT School-based AAC devices Items covered by DVA or My Aged Care Items available through community loan pools
s 34(1)(d) Informal supports

Takes into account what is reasonable to expect families, carers, informal networks and the community to provide. The criterion does not allow the NDIA to assume informal support is available. If carers are unavailable, unwilling, unable (due to health, age, geography) or if relying on them would place them at risk, this must be documented explicitly.

s 34(1)(e) NDIS most appropriate funder

The support must be most appropriately funded through the NDIS rather than through another general system. This is the boundary provision: it prevents the NDIS from funding supports that other systems (health, aged care, education, DVA) are responsible for.

Key documentation move: Where another system was approached and declined to fund the AT, document the refusal in writing and attach it. Where the need is ongoing and disability-specific rather than a time-limited health episode, state this explicitly. The longer the need has been present, the harder the “health system” argument becomes for the NDIA to sustain.

7. Common refusal reasons — and the quickest evidence fixes

Refusal reason Criterion at issue Quickest fix
“Need doesn’t arise from the NDIS impairment” s 34(1)(aa) Name the s 24 impairment. Trace the causal chain. Use Eastham para 83 language: “genuine contributory cause.” See free template pack.
“Environmental factors, not disability, are the cause” s 34(1)(aa) Note (b) Cite Note (b) directly. Environmental factors are part of the factual matrix — they do not displace the s 24 causal link.
“This is a mainstream/consumer product” Schedule characterisation Describe the item’s inherent design character for this participant’s functional need. Cite Eastham paras 106–115.
“Not value for money / cheaper alternatives exist” s 34(1)(b) Name each alternative. State why it fails this participant’s functional profile specifically. Compare costs over 2–3 years.
“More appropriately funded by the health system” s 34(1)(e) Attach any health system refusal in writing. State the need is ongoing, disability-specific and not linked to an acute health episode.
“Family/carer can provide this support” s 34(1)(d) Document carer availability, health, capacity and willingness. The test is what is reasonable to expect — not what is technically possible.

8. Evidence checklist — OT  /  SC  /  PBS practitioner

Run this checklist against your report before submission. Any unchecked box is a potential refusal risk.

Criterion What your report must address ☐ Done
s 34(1)(a) Clinical rationale specific to this participant. Evidence base, trial outcomes or published guidelines referenced by name. ☐
s 34(1)(aa) s 24 impairment named. Causal chain: impairment → functional limitation → AT need. Other conditions and environmental factors acknowledged (Note (b)). Language of “contributory cause” used. ☐
s 34(1)(b) AT cost compared to alternatives. Functional benefit stated. Quotes attached or referenced. ☐
s 34(1)(c) AT matches assessed functional needs and plan goals. Participant capacity to use the AT safely confirmed. ☐
s 34(1)(d) Informal support availability, capacity and reasonableness addressed. Carer situation documented where relevant. ☐
s 34(1)(e) Alternative funding systems addressed. Refusals by other systems documented in writing if applicable. Ongoing, disability-specific need distinguished from acute health episode. ☐
Schedule If the AT could be characterised as a consumer product: inherent design character for disability-related function described. Eastham paras 106–115 available as authority. ☐

9. Frequently asked questions

Does the NDIA have to give reasons when it refuses AT as not reasonable and necessary?

Yes. Where the NDIA makes a reviewable AT decision, it must provide a statement of reasons identifying which s 34(1) criterion was not met and why. A vague refusal (“not reasonable and necessary” without criterion-level analysis) is itself vulnerable to challenge on internal review or at the Administrative Review Tribunal.

Can the NDIA fund part of an AT request and refuse the rest?

Yes. The NDIA may approve a lower-specification item, a shorter-term trial, or a contribution toward AT that partly meets s 34(1) criteria. Where a partial approval is made, the statement of reasons should explain which components were approved and why the additional components did not satisfy the test. A partial approval is a reviewable decision.

Does the reasonable and necessary test apply at plan review, or only at initial assessment?

It applies at every plan decision including renewals and reviews. AT that was funded in a previous plan is not automatically refunded at review — the NDIA must again be satisfied that s 34(1) is met having regard to the participant’s current needs and circumstances. Changes in condition, living situation or carer availability are all relevant.

Is there a dollar threshold below which AT is funded without a formal assessment?

Not in s 34 itself. Under the 2024 NDIS Transitional Rules, certain low-cost AT supports (generally under $1,500) may be included in a plan’s Consumables budget without a formal AT assessment, depending on the support category. The underlying s 34(1) criteria still apply — the rules streamline the process, they do not modify the statutory standard.

The NDIA approved the AT item in a previous plan and is now refusing it. What has changed?

A prior approval does not bind the NDIA at plan review. However, a prior approval for the same item under the same circumstances is a strong indicator that s 34(1) can be satisfied again. Where the NDIA proposes to refuse AT that was previously funded, the statement of reasons should explain what has changed in the participant’s circumstances or in the NDIA’s assessment. An unexplained reversal is a ground for review.

What is the difference between “reasonable” and “necessary”?

The Act treats the phrase “reasonable and necessary” as a composite standard addressed through the s 34(1) criteria — there is no statutory definition that separately defines each word. In practice, “necessary” tends to relate to the disability link and functional need (s 34(1)(aa)), while “reasonable” relates to proportionality and context (s 34(1)(b)–(e)). Both concepts are evaluated against this participant’s individual circumstances.

Part of the LowCost AT NDIS AT Knowledge Base — Eligibility & Law series. Updated March 2026.

Primary sources: National Disability Insurance Scheme Act 2013 (Cth) ss 24, 25, 34  ·  CEO of NDIA v Eastham [2026] FCA 147 (Wheelahan J, 25 February 2026)  ·  National Disability Insurance Scheme Amendment (Getting the NDIS Back on Track No. 1) Act 2024 (Cth)

General information only — not legal advice. This article reflects the National Disability Insurance Scheme Act 2013 (Cth) and case law as at March 2026. LowCost AT is a provider of assistive technology products, not a legal or clinical service.