NDIS Reasonable and Necessary: What It Means and How It Affects Your Plan

"Reasonable and necessary" is the test NDIA applies when deciding what to fund in your plan. Pass the test, the support gets funded. Fail it, it doesn't. Understanding how NDIA applies this test is one of the most practically useful things an NDIS participant can know.

The phrase comes straight from the NDIS Act. Every individual support in your plan has to meet the reasonable and necessary test. If you're trying to get something funded — an assistive device, more therapy hours, a particular type of support — you need to be able to argue why it meets the test.

What "reasonable and necessary" means legally

The NDIS Act sets out seven criteria for whether a support is reasonable and necessary. To be funded, the support must:

Be related to the participant's disability.

Not include day-to-day living costs that aren't related to the disability.

Represent value for money — meaning the cost relative to the benefit is reasonable.

Be likely to be effective and beneficial for the participant.

Take account of what would be reasonable to expect from informal supports (family, friends).

Be most appropriately funded by NDIS rather than by other systems (Medicare, schools, public housing).

Not duplicate other supports the participant is already receiving.

That's the legal test. In practice, NDIA planners apply these criteria with varying degrees of rigour, and decisions can feel inconsistent. Two participants with similar circumstances can get very different decisions on similar requests.

The seven criteria, explained

Disability-related. The support has to address something caused by your disability. NDIA won't fund cooking lessons just because you'd like them. They'll fund cooking lessons if you have a disability that affects your ability to learn or perform cooking tasks safely. The connection has to be clear.

Not day-to-day costs. NDIA doesn't fund things everyone has to pay for regardless of disability — rent, groceries, utility bills, general clothing, regular furniture. These are excluded by design.

Value for money. This is one of the trickier criteria. NDIA looks at whether what you're asking for is the most cost-effective option for achieving the same outcome. If a $10,000 piece of equipment achieves the same as a $4,000 alternative, they may only fund the cheaper option.

Likely to be effective. NDIA wants evidence that the support actually helps. For new or emerging therapies, you may need to show research evidence or professional recommendation.

Reasonable informal support. NDIA assumes families and friends provide some level of support. They won't fund a paid carer to do things they expect a parent or partner to do. This is one of the most contested criteria — what's "reasonable" to expect from family is subjective.

Most appropriately funded by NDIS. NDIS is the funder of last resort for many supports. They won't fund things that should be paid by Medicare, the education system, the housing system, or the health system.

Not duplicating. If you're already getting a support funded by another system or another part of your NDIS plan, NDIA won't double-fund it.

Common reasons requests are rejected

Some recurring patterns in why supports get knocked back:

Insufficient evidence of disability link. You asked for a support but didn't establish how it specifically addresses your disability-related needs.

Mainstream system responsibility. The support is something Medicare, schools, or the health system should provide.

Informal support assumed. NDIA decided your family or partner could reasonably provide the support without payment.

Cost concerns. A cheaper option exists that NDIA considers comparable.

Lack of evidence of effectiveness. Especially for newer therapies, alternative therapies, or unusual requests.

Goal misalignment. The support doesn't clearly relate to the goals listed in your plan.

How to argue for a support

If you're trying to get something funded, here's how to build a strong case.

Get specific evidence from a relevant clinician. The strongest evidence is usually from an OT, psychologist, or specialist who has assessed you and can write a report explaining exactly why the support is needed and how it addresses your disability.

Address each of the seven criteria explicitly. Don't just say "I need more therapy." Explain why it's disability-related, how it represents value for money compared to alternatives, what informal supports you have or don't have, and why this isn't the responsibility of another funding system.

Use NDIS terminology. NDIA decisions are made by people who think in NDIS frameworks. Frame your argument in those terms — disability-related, capacity-building, functional impact.

Provide quotes or comparison costs if you're requesting equipment. Showing that you've researched alternatives strengthens the value-for-money argument.

Tie the support to a specific goal. If your goal is "increase community participation," and you're asking for transport funding, the connection is straightforward. If you're asking for something that doesn't fit your stated goals, consider whether your goals need updating first.

Examples of funded vs unfunded requests

Usually funded:

Personal care support hours related to ADL impairment.

OT for assistive technology assessment and prescription.

Support coordination for participants with complex needs.

Wheelchair, walking aids, or other mobility equipment with OT assessment.

Behaviour support therapy for participants with challenging behaviours.

Plan management.

Often refused without strong evidence:

Alternative or unproven therapies (e.g. hyperbaric oxygen, certain dietary programs, music therapy without a clear disability link).

Gym memberships (NDIA generally considers these mainstream).

Holidays and travel (almost never funded as a standalone item).

Pet-related costs (assistance animal funding is possible but heavily regulated).

Items also available through Medicare or another scheme.

Capital supports without prior assessment or quote.

Frequently asked questions

Can I appeal a decision that something isn't reasonable and necessary?

Yes. Request an internal review within three months of the decision. Provide additional evidence and address each criterion specifically. If internal review is unsuccessful, you can apply to the AAT.

Why does my friend have something funded that I was refused?

NDIA decisions are individualised. Two participants with similar conditions can get different outcomes depending on the evidence provided, the planner involved, and the specifics of how each request was framed. It's frustrating but not unusual.

Does the seven-criteria test apply to every support in my plan?

Yes. Every funded support is theoretically tested against the seven criteria. In practice, common supports (personal care, basic therapy) get approved without much explicit reasoning. Unusual or higher-cost requests get more scrutiny.

What if my situation changes and a previously refused support is now needed?

Request a plan amendment or unscheduled review. Provide the new evidence. Old refusals don't bind future decisions if circumstances change.

If you're trying to argue for a support and not sure how to frame it, your support coordinator should help with this — preparing evidence and addressing the seven criteria is core coordination work. Seareal's coordinators do this regularly across Queensland.