Does a support have to meet all the criteria?

Yes. A support must satisfy every part of the reasonable and necessary test, not just one or two criteria. It needs to relate to your disability, help you pursue your goals, be value for money, be likely to be effective, take account of informal and mainstream supports, and be most appropriately funded by the NDIS rather than another system.

Does value for money mean the cheapest option?

No. Value for money means the cost of a support is reasonable compared with the benefit it provides and with other ways of achieving the same result. Sometimes a more expensive support is good value if it builds your independence or reduces the need for other supports over time. The question is whether the benefit justifies the cost.

Will having family support reduce my funding?

The NDIA takes account of informal supports, such as help from family and carers, when deciding what is reasonable and necessary. This does not mean your family is expected to do everything, or that you get nothing. It means the full picture is considered so funded supports work alongside the natural supports around you rather than simply replacing them.

Why was a support rejected as not reasonable and necessary?

Usually because it did not meet one or more parts of the test. Common reasons include no clear link to your disability, weak evidence it will be effective, poor value for money, or that another system such as health or education should provide it. Understanding which criterion was not met helps you decide whether to provide more evidence or seek a review.

How can I show a support is effective and beneficial?

Provide evidence. Reports or letters from therapists, doctors or other professionals can show a support is likely to work and to help your situation. Explain clearly how the support responds to your disability and your goals. Concrete detail about your circumstances and expected outcomes is far more persuasive than a general request without any supporting information.

Where do the reasonable and necessary criteria come from?

The criteria come from the NDIS Act, the law that established the NDIS. They are explained in plain language in the NDIS Our Guidelines on ndis.gov.au. The criteria cover the link to your disability, your goals and independence, value for money, likely effectiveness, informal and mainstream supports, and whether the NDIS is the most appropriate system to fund the support.

Reasonable and necessary — the tests every support must pass

The criteria the NDIA weighs before it funds a support, explained in plain English.

Before the NDIA funds any support in your plan, it applies a test known as 'reasonable and necessary'. If you have ever wondered why one support was approved and another was not, this test is usually the reason.

This guide explains the reasonable and necessary criteria in plain English, so you can understand what the NDIA is looking for and how to show that a support you want meets the test. It is general information from Novida, an independent directory, not advice from the NDIA.

In this guide

Reasonable and necessary is the test the NDIA uses before funding any support.
The support must relate to your disability and help you pursue your goals.
It must represent value for money and be likely to be effective and beneficial.
It should take account of support from family, carers, community and mainstream services.
It must be most appropriately funded by the NDIS rather than another system like health or education.

What "reasonable and necessary" means

Reasonable and necessary is the standard the NDIA applies to decide whether a support can be included in your plan. Every support that is funded has to meet this test, which is set out in the law that created the NDIS, the NDIS Act.

In plain terms, 'reasonable' means the support is fair and sensible given your situation, and 'necessary' means you genuinely need it because of your disability. A support has to satisfy a set of criteria before it can be funded, and it needs to meet all of them, not just one or two.

Understanding these criteria is useful because it helps you frame your requests. Rather than simply asking for a support, you can explain how it ticks each box. That makes it easier for a planner to see why the support belongs in your plan.

Related to your disability and your goals

The first thing a support must do is relate to your disability. If there is no clear link between the support and the challenges your disability creates, it will not meet the test. This is why the connection to your disability comes up again and again.

The support should also help you pursue your goals and increase your independence. The NDIS is focused on helping you take part in everyday life, including social and economic participation, which can mean things like being more involved in your community, building skills, or working towards employment.

This is where your goals matter. When your plan includes clear goals, it becomes much easier to show that a support connects to them. A support that helps you become more independent, or take part more fully in life, fits squarely with what the NDIS is designed to do.

Value for money and effectiveness

The NDIA also looks at whether a support represents value for money. This does not simply mean the cheapest option. It means the cost is reasonable compared with the benefit it provides, and compared with other ways of achieving the same outcome.

Sometimes a support that costs more up front can be good value if it reduces the need for other supports over time, or helps you become more independent. The question is whether the benefit justifies the cost, not just the price tag on its own.

Alongside value for money, the support must be likely to be effective and beneficial for you. In other words, there should be good reason to expect it will actually work and help you. This is where evidence matters, such as advice from a therapist or other professional showing the support is likely to make a real difference for your situation.

Informal supports and other systems

The NDIS does not exist on its own. When deciding what is reasonable and necessary, the NDIA takes account of the informal supports already in your life, such as help from family, carers, friends and the community.

This does not mean the NDIS expects your family to do everything, or that having support at home means you get nothing. It means the whole picture is considered, so that funded supports work alongside the natural supports around you rather than replacing them entirely.

Mainstream and community services are also part of the picture. Things that are usually provided by other service systems, such as health, education or the community more broadly, are expected to be delivered by those systems. The NDIS looks at what is already available before funding a support itself.

How to show a support meets the test

Because a support must satisfy every part of the test, the best approach is to address each part when you ask for it. Explain how the support relates to your disability, how it helps you pursue your goals and become more independent, and why it is good value.

Evidence helps a great deal. Reports or letters from therapists, doctors or other professionals can show that a support is likely to be effective and beneficial, and that it is the right response to your needs. Concrete detail about your situation is more persuasive than a general request.

It also helps to show why the NDIS is the right system to fund the support, rather than health, education or another service. If you can explain that clearly, and point to how the support fits your goals, you make it far easier for a planner to include it. The NDIS Our Guidelines on ndis.gov.au set out the criteria in full.

Frequently asked questions

What does reasonable and necessary actually mean?: It is the test the NDIA uses to decide whether a support can be funded in your plan. 'Reasonable' means the support is fair and sensible for your situation, and 'necessary' means you genuinely need it because of your disability. A support has to meet every part of the test, which is set out in the NDIS Act, before it can be included in a plan.
Does a support have to meet all the criteria?: Yes. A support must satisfy every part of the reasonable and necessary test, not just one or two criteria. It needs to relate to your disability, help you pursue your goals, be value for money, be likely to be effective, take account of informal and mainstream supports, and be most appropriately funded by the NDIS rather than another system.
Does value for money mean the cheapest option?: No. Value for money means the cost of a support is reasonable compared with the benefit it provides and with other ways of achieving the same result. Sometimes a more expensive support is good value if it builds your independence or reduces the need for other supports over time. The question is whether the benefit justifies the cost.
Will having family support reduce my funding?: The NDIA takes account of informal supports, such as help from family and carers, when deciding what is reasonable and necessary. This does not mean your family is expected to do everything, or that you get nothing. It means the full picture is considered so funded supports work alongside the natural supports around you rather than simply replacing them.
Why was a support rejected as not reasonable and necessary?: Usually because it did not meet one or more parts of the test. Common reasons include no clear link to your disability, weak evidence it will be effective, poor value for money, or that another system such as health or education should provide it. Understanding which criterion was not met helps you decide whether to provide more evidence or seek a review.
How can I show a support is effective and beneficial?: Provide evidence. Reports or letters from therapists, doctors or other professionals can show a support is likely to work and to help your situation. Explain clearly how the support responds to your disability and your goals. Concrete detail about your circumstances and expected outcomes is far more persuasive than a general request without any supporting information.
Where do the reasonable and necessary criteria come from?: The criteria come from the NDIS Act, the law that established the NDIS. They are explained in plain language in the NDIS Our Guidelines on ndis.gov.au. The criteria cover the link to your disability, your goals and independence, value for money, likely effectiveness, informal and mainstream supports, and whether the NDIS is the most appropriate system to fund the support.

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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.