What Happens in a Functional Behaviour Assessment Under the NDIS
A functional behaviour assessment is how a behaviour support practitioner works out why a behaviour of concern happens and what need it meets. Once that reason is clear, support can focus on the need rather than the behaviour. 2b Inclusive is a registered NDIS provider completing these assessments across Adelaide.
Key Takeaways
Each functional behaviour assessment looks for the purpose behind a behaviour, using interviews, observation and ABC data.
Only a practitioner the NDIS Commission finds suitable can carry out the assessment.
Families and support workers help by recording what happens and sharing what they know.
Findings shape a full behaviour support plan, and the assessment is revisited every 12 months or sooner.
What Is a Functional Behaviour Assessment?
Put simply, a functional behaviour assessment is a structured process for understanding the function, or purpose, of a person's behaviour. The NDIS Commission's FBA practice guide, released in April 2026, describes it in those terms. Behaviour is treated as communication. It tells us something the person may not be able to say another way.
Common purposes include a break from something too hard or too loud, connection with a trusted person, access to a preferred item, and seeking or avoiding sensory input. Two people can show the same behaviour for very different reasons. That is why copying a strategy that worked for someone else often fails.
Under the NDIS, a functional behaviour assessment sits inside a wider behaviour support assessment. That broader view also covers health, mood, communication, relationships and surroundings. The Commission calls this a biopsychosocial view. So expect questions about sleep, pain or recent changes at home, not just about incidents.
Why Does Behaviour Support Start With an FBA?
Positive behaviour support begins with understanding. A plan built without it tends to manage symptoms, not meet needs. If a young person runs from class to escape noise, a reward chart will not fix the noise. A functional behaviour assessment points the plan towards quieter spaces, warnings before loud events and a safe way to ask for a break.
Quality of life sits at the centre of this work. The Commission expects baseline data on quality-of-life measures as well as on the behaviour. In other words, a functional behaviour assessment sets up success as a fuller life, not only fewer incidents. In our neurodiversity-affirming practice, we look at the environment and how others respond before asking the person to change.
Reducing regulated restrictive practices is the other big reason. Restraint and seclusion are tightly regulated. The Commission wants them reduced and, where possible, removed. Knowing why behaviour happens is what makes safer alternatives possible.
Who Can Carry Out a Functional Behaviour Assessment?
Only an NDIS behaviour support practitioner found suitable by the NDIS Commission can complete the assessment activities. Suitability is judged against the Positive Behaviour Support Capability Framework. That framework sets out four levels: core, proficient, advanced and specialist.
Providers also need the right registration. The Commission's guide says providers must be registered under section 73E of the NDIS Act to deliver this kind of behaviour support. Someone not yet found suitable cannot carry out the assessment, even under supervision.
Other people still play a big part in a functional behaviour assessment. Parents, carers, support workers, teachers and therapists can collect information, record incidents and share what they have noticed. Your plan manager or support coordinator can help you check that a provider is registered before you start.
How Does a Functional Behaviour Assessment Work?
Most assessments follow a similar path, though the detail changes for each person. The steps below match the process in the Commission's guide.
Much of a functional behaviour assessment happens in everyday places, not a clinic. Our practitioners travel to homes and community settings across Northern, Southern, Eastern and Western Adelaide. Seeing the person in their own routine usually gives a clearer picture than a single office visit.
1. Consent and Getting to Know the Person
Consent comes first. The practitioner explains what information will be collected, how it will be stored and who will see it. The person and, where relevant, their guardian are asked to agree. Supported decision making means the person has a say in their own assessment, in whatever way they communicate.
2. Describing the Behaviour Clearly
Clear descriptions make the data useful. "Becomes anxious" or "has a meltdown" means different things to different people. The guide asks for behaviour described in observable, measurable terms, such as "pushes the plate off the table". Diagnoses and feelings are not used as behaviour descriptions.
3. Gathering Background Information
Interviews with the person and their supporters come next, along with past reports and records. Practitioners may use questionnaires such as the Functional Analysis Screening Tool (FAST). This stage maps setting events, early warning signs and strategies already tried.
4. Observing and Recording Data
Direct observation shows what really happens during a functional behaviour assessment. ABC data (antecedent, behaviour, consequence) records what came just before, what happened and what followed. Baseline data on frequency, duration and intensity gives a starting point to measure change against.
5. Making Sense of the Pattern
Analysis brings everything together. The practitioner separates triggers from setting events. The guide also notes that the maintaining consequence (what follows the behaviour) is not the same as the function (why it happens). A formulation then looks at predisposing, precipitating, perpetuating and protective factors.
What Will Families and Support Workers Be Asked to Do?
Families are usually asked for time, knowledge and some simple record keeping during a functional behaviour assessment. Expect an interview about history, routines, health, communication and what a good day looks like. Practitioners also ask what has helped in the past, because small wins often hold clues.
Support workers and implementing providers may be asked to fill in ABC charts after incidents, or to note when a good day happens. The Commission expects implementing providers to help, such as by freeing up staff for interviews. Short notes made soon after an event beat long accounts written days later.
Before the first visit, it helps to gather:
Any previous behaviour support plans, reports or school plans
Notes on recent incidents, even rough ones
Your usual weekly routine, including sleep and meals
What calms the person and what seems to upset them
A Pattern We Often See
Here is a general, de-identified pattern. An adult leaves the house abruptly before group outings. Early guesses point to defiance, but interviews and ABC data show it mostly happens when plans change at short notice.
Escaping uncertainty turns out to be the function. So the plan focuses on visual schedules and earlier notice of changes, rather than consequences for leaving.
How Long Does It Take and How Is It Funded?
Timeframes for a functional behaviour assessment vary. They depend on how often the behaviour happens and how many settings are involved. Where a regulated restrictive practice is used, the Commission's behaviour support fact sheet sets limits. An interim plan is due within 1 month and a full plan within 6 months of the practitioner being engaged.
Interim plans keep everyone safe while the functional behaviour assessment is under way. The guide describes an interim behaviour support plan as a short document with general prevention and response strategies. It does not replace the full assessment, and the full plan must be based on one.
Funding for behaviour support usually comes from the Capacity Building, Improved Relationships budget in an NDIS plan. Services may be funded where they align with your goals and budget, so check with your plan manager or support coordinator first. We can help you see whether your plan includes this funding before you begin.
What You Get at the End
Every completed functional behaviour assessment produces a written behaviour assessment report. The guide asks for a summary of findings rather than raw data, and lists 21 elements the report should cover. These include sources of information, clear behaviour descriptions, triggers and consequences, a function statement and recommended referrals.
That report becomes the foundation of the full behaviour support plan. Where a plan includes regulated restrictive practices, the NDIS Restrictive Practices and Behaviour Support Rules set how it is developed, what it contains and how it is reviewed. Those plans are reviewed at least every 12 months, and the assessment itself should be updated sooner if life changes.
Ask for a meeting to go through the report so everyone agrees on what it found. Next, read what a behaviour support plan includes. If you want to start, ask our positive behaviour support in Adelaide team for an assessment.
Frequently Asked Questions
Is there an NDIS functional behaviour assessment template?
No single mandatory template exists. Instead, the Commission's 2026 guide lists what a report should include. Each registered provider builds its own format around that list. Ask your practitioner to walk you through their report layout so you know what to expect.
Can an FBA be done at school or at home?
Yes, and often both. Schools use the same approach for students who need extra help, and the NSW Department of Education explains how teachers use ABC data. Under the NDIS, a functional behaviour assessment that covers several settings gives a clearer picture.
Do I need a diagnosis to get an FBA?
A diagnosis is not what starts a functional behaviour assessment. Behaviours of concern and an NDIS plan with behaviour support funding are the usual starting point. People we support include those with autism, ADHD, intellectual disability, acquired brain injury, dementia and psychosocial disability, among others.
Can I see the FBA report?
You should be able to. Consent and supported decision making run through the whole process. The person and their family or guardian should be part of discussing the findings. Ask how the report will be shared and who else will receive a copy, such as an implementing provider.
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