Reasonable and necessary

The test the NDIA uses to decide which supports it will fund in your plan.

What it means

Reasonable and necessary is the test the National Disability Insurance Agency (NDIA) must apply before it agrees to fund a support in your plan. It is not about what would simply be nice to have, or everything a person might want. It is a set of criteria that a support has to meet before the NDIS will pay for it.

To be reasonable and necessary, a support must relate to your disability, and help you work towards the goals in your plan. It must represent value for money, and be likely to be effective and beneficial for you. The NDIA also looks at the informal supports already around you, such as help from family, friends and your community, and considers whether the support is most appropriately funded by the NDIS rather than by another system such as health or education.

In practice

When you ask for a support, it helps to explain how it connects to your disability and your goals, and why it is the most suitable option. Evidence from allied health professionals, such as an occupational therapist or physiotherapist, can show that a support is likely to be effective and good value.

The NDIA weighs each criterion together, not in isolation. A support might clearly relate to your disability but still be declined if another service system is responsible for it, or if there is a more cost-effective option that meets the same need. If you disagree with a decision, you can ask for a review of that decision. Understanding the test helps you build a stronger case and know what information to provide.

A real example

For example, Priya has cerebral palsy and a goal to travel to her part-time job independently. Her occupational therapist recommends training to use public transport safely, and explains how it links to her disability and goal. Because it is good value and helps her build independence, the NDIA agrees it is reasonable and necessary.

Reasonable and necessary — FAQs

What does reasonable and necessary actually mean?
It is the test the NDIA applies before funding any support. The support must relate to your disability, help you pursue your goals, be value for money, be likely to be effective and beneficial, take account of informal supports, and be something the NDIS should fund rather than another system. All these criteria are considered together.
Who decides if a support is reasonable and necessary?
The NDIA makes the decision, guided by the criteria set out in NDIS law. A planner or delegate reviews your request, the evidence you provide, and your goals. Reports from allied health professionals and other supporting information help the delegate weigh up whether each criterion is met before approving funding.
Why was my support decided not to be reasonable and necessary?
A support can be declined if it does not clearly relate to your disability, does not link to your goals, is not good value for money, or is the responsibility of another system like health or education. Sometimes more evidence is needed. The decision letter should explain the reason, and you can ask for a review.
Does reasonable and necessary mean I only get the cheapest option?
No. Value for money is only one of the criteria, and it is balanced against effectiveness and benefit. The NDIA looks for supports that genuinely help you and represent sound value, not simply the cheapest available. If a lower-cost option would not meet your needs, that can be part of your case.
How can I show a support is reasonable and necessary?
Explain how the support relates to your disability and helps you reach a goal in your plan. Provide evidence, such as reports from your therapists or doctors, showing it is likely to be effective and good value. Note any informal supports you already have, and be clear about why the NDIS is the right funder.

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Official NDIS sources

Novida is an independent directory, not the NDIA. We explain each form in plain English and link you to the official copy — always download and submit the current version from the official website, as forms are updated from time to time.