"Reasonable and necessary" is one of the most important phrases in the NDIS. It is the test for what goes in your plan. This guide explains it in plain words.
What the phrase means
The NDIS does not pay for everything. It pays for supports that are reasonable and necessary for you. Each support in your plan has to meet the test. The plan as a whole also has to make sense.
The test is set out in the NDIS law and rules. The NDIS explains it in its guidelines. We link to those below.
The main criteria
According to the NDIS guidelines, a support should meet these ideas.
It helps with your goals. The support helps you pursue the goals in your plan.
It helps you take part in life. It helps you reduce barriers to social and economic participation. That includes things like recreation, work and study.
It is good value for money. The NDIS compares the cost with the benefit. It may also compare it with other options.
It is effective. It is likely to work and be helpful, based on current good practice.
It relates to your disability. The support is linked to your disability support needs.
It is an NDIS support. It is something the NDIS can fund. The NDIS publishes lists of what it can and cannot fund.
It complements other supports. NDIS supports are meant to work alongside, not replace, what you can do yourself and what you get from family, friends, community and other government services.
Why the "package" matters
The NDIS also looks at your supports together. Each one has to be reasonable and necessary. And they have to work as a set.
For example, home modifications might reduce how much other help you need. Or a therapy program might reduce how many support hours you need later. The NDIS may adjust one thing because of another.
What is not funded
The NDIS says it cannot fund supports that:
- are day-to-day living costs, such as rent, groceries and bills
- are illegal
- should be funded by another government system or community service
- are not an NDIS support under its lists
Since 3 October 2024, the NDIS has used lists of what can and cannot be funded. There is more detail on the NDIS website. Check it before buying something.
What other services do
Systems such as health and education have their own duties. The NDIS looks at what those systems should provide. It also looks at reasonable adjustments required under discrimination laws.
This means some supports that sound helpful are not funded because another system is meant to provide them.
How to make your case
You can help the NDIS understand your needs. A few steps:
- Link it to a goal. Say how this support helps your goal.
- Explain the impact. Describe how your disability affects this part of your life.
- Use evidence. Reports from therapists or doctors can help. They should say what is recommended, how often, and why.
- Show it is fair value. Be ready to explain why this option suits you better than others.
- Say what you have tried. Include things that did not work.
- Keep records. Note how supports have helped so far.
See also NDIS plan reassessment: what to expect for how to prepare.
What is changing
Reforms passed in 2026 changed parts of the test. Government documents say new criteria apply to new plans and will be applied progressively to current participants as their plans are reassessed. They also say new guidance clarifies what parents are expected to provide for children, such as supervision and personal care.
Details are still being worked through. Check ndis.gov.au for the current rules, and ask your NDIS contact how they apply to your plan.
If the answer is no
If the NDIS decides a support is not reasonable and necessary:
- Ask for the reasons in writing.
- Ask what evidence might change the answer.
- Ask for an internal review. You have three months from when you receive the decision in writing.
- Get help from an advocate, family member or support coordinator.
Read what to do if something goes wrong with a provider for more help.
Example: two requests, two outcomes
Imagine two people ask for a similar support.
Request A: "I would like weekly sessions with an occupational therapist to learn to cook safely. My goal is to live more independently. Here is my therapist's report."
Request B: "I would like an expensive gadget. I saw it online and think it would be nice."
Request A links to a goal, shows the impact of the disability, includes evidence and explains why the support is likely to help. Request B does not. The NDIS has much more to work with in A.
This does not mean you can only ask for things that are "needed to survive". The test also looks at taking part in work, study, community and social life. But you do need to explain the link to your disability and your goals.
Tips for talking with the NDIS
- Use your own words.
- Give examples from your life, not just labels.
- Say what happens if you do not get the support.
- Say what you have already tried.
- Ask what extra information would help.
About this guide
Goodo is independent. We are not part of, or endorsed by, the NDIA or the NDIS Quality and Safeguards Commission. This is general information, not advice. Rules change, so check ndis.gov.au or call the NDIS on 1800 800 110 about your own situation.
Frequently asked questions
What does reasonable and necessary mean?
It is the test the NDIS uses to decide if it will fund a support. A support must meet several criteria, such as helping you pursue your goals, being linked to your disability, being good value for money, and being likely to work.
Is everything related to my disability funded?
No. The NDIS funds supports that are NDIS supports and meet the criteria. It does not fund day-to-day living costs such as rent or groceries, or things that other government systems should provide.
What can I do to show a support is reasonable and necessary?
Link it to your goals. Explain how your disability affects this area. Bring evidence such as a report from your therapist. Show how it helps you take part in life, and why it is good value.
Are the rules changing?
Yes. Government documents say updated criteria apply to new plans from 2026 and will be applied progressively to current participants as their plans are reassessed. Check ndis.gov.au for the latest.
What if the NDIS says no to a support?
Ask for the reasons in writing. You can ask for an internal review within three months of getting the decision. You can get help from an advocate.
Sources
Goodo is independent