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Functional behaviour assessment (FBA)

A functional behaviour assessment (FBA) is how an NDIS behaviour support practitioner works out what a behaviour of concern is doing for a person: what sets it off, what keeps it going and what need sits underneath. At CHSA it's part of our positive behaviour support service across Adelaide, at home, school, in the community or at our clinics, funded from the participant's NDIS Improved Relationships budget.

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The first call with our team is free. We usually reply within 1–2 business days.

An FBA at a glance

What it is
Working out the purpose (function) of a behaviour of concern
Who does it
An NDIS behaviour support practitioner at a registered provider
When
While an interim plan is in place, before the comprehensive plan (within 6 months)
How
Talking with people, questionnaires, observation and ABC records
Leads to
A comprehensive behaviour support plan
Paid from
NDIS Capacity Building – Improved Relationships
At CHSA
Part of our PBS service, not sold separately; first call free
Reviewed
At least every 12 months, or sooner if things change

What is a functional behaviour assessment?

NDIS rules describe a functional behaviour assessment as the process of working out and understanding the function, or purpose, behind a person's behaviour.1 In plain words: every behaviour does a job for the person, such as getting a break, connection, something they want, or relief from a feeling in their body. An FBA (sometimes written "functional behavioural assessment") finds that job, so support can meet the same need in a safer, easier way.

Under the NDIS, the FBA is one part of a wider behaviour support assessment that also looks at health, communication, sensory needs, relationships and quality of life.1 It's the foundation of positive behaviour support, where behaviour is treated as communication, not defiance.

An FBA looks at behaviours of concern: behaviours that put the person or others at risk, or get in the way of everyday life. It looks at situations and needs, and doesn't judge the person.

When does the NDIS require a functional behaviour assessment?

If an NDIS participant needs specialist behaviour support, the NDIS Quality and Safeguards Commission sets these rules:

  • The comprehensive plan must be based on it a comprehensive behaviour support plan has to be built on a behaviour support assessment, including an FBA1
  • Only an NDIS behaviour support practitioner can do it someone the NDIS Commission considers suitable, working for a provider registered for specialist behaviour support1
  • An interim plan comes first an interim behaviour support plan is due within 1 month, so there's support while the assessment happens3
  • The comprehensive plan follows within 6 months based on what the assessment found3
  • It's revisited at least every 12 months or sooner if the person's life or needs change2

Schools have their own processes for students. It's always the person's choice of provider.

What are the four functions of behaviour?

Practitioners often group the purpose of a behaviour into four functions. The grouping comes from behaviour research (Iwata and colleagues, 1982 and 1994); it's a common way to think about function, not an NDIS rule.

  • Connection and attention getting time, interaction or reassurance from someone
  • Escape or avoidance getting away from a task, place, noise or demand that feels like too much
  • Access to things or activities getting an item, food, activity or more time with something they enjoy
  • Sensory the behaviour itself soothes, feels good, or blocks out discomfort or pain. Read about sensory processing differences

The NDIS Commission's practice guide adds two cautions: one behaviour can serve more than one function, and a diagnosis (such as autism) or "power and control" should not be described as the function.2 It also asks practitioners to describe what a behaviour looks like rather than use labels like "tantrum".2

What does a functional behaviour assessment example look like?

This example is made up. An FBA looks at what happens just before a behaviour, the behaviour itself, and what happens straight after: the ABC (antecedent, behaviour, consequence).

  1. Before

    Sam is tired after a poor night's sleep. In a busy shopping centre, a hand dryer starts loudly.

  2. Behaviour

    Sam covers their ears, shouts and pushes past people to get out.

  3. After

    A support worker takes Sam outside to a quiet spot, and the noise stops.

…so pushing out of loud places is more likely next time.

An example summary (a "hypothesis"): when Sam is tired and in a loud place, sudden noise is likely to lead to shouting and pushing, which gets Sam away from the noise. A plan might then help Sam ask for a break with a card or sign, and use ear defenders and quieter routes.

How is the information gathered?

A good FBA uses more than one source and looks at every place the behaviour happens. The NDIS Commission doesn't prescribe particular assessment tools.2 Common methods include:

  • Talking with the person in the way that works for them, with communication aids and support to make decisions
  • Interviews with family, carers, teachers and support workers who know the person well
  • Questionnaires standardised measures; the Commission's practice guide gives examples such as the FAST and QABF2
  • Past reports OT, speech pathology, medical and school reports, and any earlier behaviour support plans
  • Observation watching what happens in everyday places, such as home, school or the community
  • Records over time ABC notes, how often and how long a behaviour happens and how intense it is, and scatterplots showing times of day

How long does a functional behaviour assessment take?

Every FBA is different, because it depends on the person, how many places behaviours happen in and how much information is already there. At CHSA, the FBA is one part of the whole PBS service, and it usually fits into the steps below.

  1. A free first call

    Call 08 8166 4700 or refer online. We usually reply within 1–2 business days.

  2. Referral and service agreement

    We gather the NDIS plan details and goals, agree a service agreement with you, including the hours we quote, and match you with a behaviour support practitioner.

  3. Initial consultation

    A 90-minute meeting with the person and the people who support them.

  4. Interim behaviour support plan

    Within 1 month if one is needed, so there's support while the assessment happens.

  5. Gathering information

    Interviews, observation and records in the places that matter to the person.

  6. Using what the FBA found

    The FBA is a vital source of data: your practitioner analyses it to shape the strategies in the comprehensive plan, which they write with you within 6 months. The FBA is usually shared with the care team, and you can talk it through with them and your practitioner.

  7. Training and review

    Training for the people who use the plan, and a review at least every 12 months, or sooner if things change.

What goes in an FBA report?

The NDIS Commission doesn't publish one official FBA template. Its practice guide recommends a separate assessment report as best practice, written as a summary rather than raw data.2 At CHSA, the FBA informs the strategies in the comprehensive behaviour support plan, and it's usually shared with the person's care team. In plain words, it usually covers:

  • Background the person, their strengths, history and health
  • Methods who was spoken with, what was observed, and which tools were used
  • Target behaviours what each behaviour looks like, how often, how long and how intense
  • Triggers what tends to happen just before
  • Setting events background things, such as pain, poor sleep or a change in routine
  • What keeps it going what happens afterwards that makes it more likely next time
  • Function statement the best explanation of what the behaviour does for the person
  • Formulation how it all fits together, including quality of life
  • Replacement skills safer ways to meet the same need
  • Recommendations what the behaviour support plan should include

The Commission's interim and comprehensive behaviour support plan templates are separate from the assessment report.4

How does the FBA shape the behaviour support plan?

The function found in the FBA drives the plan. If a behaviour gets someone away from noise, the plan works on the noise and on easier ways to ask for a break, not on punishment.

A behaviour support plan built on an FBA usually includes changes to the environment and routine, new skills that meet the same need, and ways to support the person when things start to get hard, decided with the person as much as possible. A goal of PBS is also to reduce and, where possible, remove restrictive practices; restrictive practices in South Australia explains how that works.

How can families, carers and support workers help?

The NDIS Commission says family, support workers and others should play a role in collecting information.1 That might mean:

  • Keeping simple ABC notes the date and time, what happened just before, what you saw (describe it, don't label it), and what happened straight after
  • Noticing the background sleep, pain, hunger, busy places or changes in routine
  • Sharing reports OT, speech pathology, medical and school reports, and earlier plans
  • Sharing what goes well strengths, interests and what already helps
  • Agreeing who's involved the person, with support if needed, decides who is asked and what is shared
  • Including school with consent, our practitioners work with teachers and school staff, who can share notes and plans

If sensory needs play a big part, our occupational therapists may be able to add a sensory assessment. [Confirm: how PBS and OT work together on this]

Is an FBA the same as a functional capacity assessment?

No. The names are similar, but they answer different questions.

Functional behaviour assessment
Done by an NDIS behaviour support practitioner. Asks why a behaviour of concern happens. Leads to a behaviour support plan.
Functional capacity assessment
Done by an occupational therapist. Looks at what a person can do day to day, such as self-care, home and community tasks. Often used as evidence for NDIS planning. See functional capacity assessments.

Who does functional behaviour assessments at CHSA?

Every one of our eight behaviour support practitioners does functional behaviour assessments, as part of the whole PBS service rather than a separate one. They bring backgrounds in psychology, social work, disability studies and behaviour analysis, and between them support children, teenagers and adults. Rowena Cornish and Jess Valerio are the team's two clinical supervisors, and every assessment and plan is guided by supervision and team review. All our behaviour support practitioners are assessed as suitable by the NDIS Commission.7

What does an FBA cost, and how is it funded?

The FBA isn't charged as a separate package. It's part of your behaviour support hours.

Hourly rate
$252.99 per hour, the 2026–27 national NDIS price limit for Specialist Behavioural Intervention Support, item 11_022_0110_7_3.5
Travel
Charged at 50% of the hourly rate.
How many hours
It depends on the person. We quote the hours in your service agreement before work starts.
Which budget
Capacity Building – Improved Relationships.6 If behaviour support isn't in the plan yet, talk to your support coordinator or LAC about a plan review.
Plan types
We accept NDIA-managed, plan-managed and self-managed plans. Our PBS service is NDIS-funded only.

All PBS fees are on the positive behaviour support page. How we deliver services is on our service delivery page.

Common questions about functional behaviour assessments

Who is qualified to do a functional behaviour assessment under the NDIS?

Only an NDIS behaviour support practitioner the NDIS Commission considers suitable, working for a provider registered for specialist behaviour support.1 You can look up practitioners on the Commission's finder.7 Schools run their own processes (in the US it's called a "functional behavior assessment"). Read more about what a behaviour support practitioner does.

Is there an NDIS functional behaviour assessment template?

No single official template. The NDIS Commission's practice guide lists what an assessment report should include,2 and the Commission publishes templates for interim and comprehensive behaviour support plans.4 See what goes in an FBA report.

Does the NDIS pay for an FBA?

Yes, when a participant has funding for behaviour support. It usually comes from the Capacity Building – Improved Relationships budget.6 See cost and funding.

Can an FBA be done by telehealth?

Parts of it can. We use telehealth for meetings, reviews and training, so some interviews can happen that way. Watching what happens in everyday places means visiting them. Your practitioner will talk with you about what suits.

How often is an FBA updated?

At least every 12 months, or sooner if the person's life, health or support changes.2

Is an ABC chart the same as an FBA?

No. An ABC chart is one way to collect information. The FBA brings together ABC notes, interviews, observation and reports to work out the function of a behaviour.

References

  1. NDIS Quality and Safeguards Commission. (2025). Policy guidance: Behaviour support assessment, including functional behaviour assessment (V1.0) [Confirm: exact page title]. https://www.ndiscommission.gov.au/sites/default/files/2025-06/Policy%20Guidance%20-%20Behaviour%20Support%20Assessment%20including%20FBA%20-%20V1.0%2023%20May%202025.pdf (accessed 3 November 2026).
  2. NDIS Quality and Safeguards Commission. (2026). Behaviour support assessment, including functional behaviour assessment: Practice guide (V1.0). https://www.ndiscommission.gov.au/sites/default/files/2026-05/Behaviour-Support-Assessment-FBA-Guide-PDF.pdf (accessed 3 November 2026).
  3. NDIS Quality and Safeguards Commission. (n.d.). Participant fact sheet 4: What to expect from your specialist behaviour support provider. https://www.ndiscommission.gov.au/sites/default/files/2025-12/Participant%20Fact%20Sheet%20-4%20-%20What%20to%20expect%20from%20your%20specialist%20behaviour%20support%20provider.pdf (accessed 3 November 2026).
  4. NDIS Quality and Safeguards Commission. (n.d.). How to develop behaviour support plans. https://www.ndiscommission.gov.au/rules-and-standards/behaviour-support-and-restrictive-practices/how-develop-behaviour-support-plans (accessed 3 November 2026).
  5. National Disability Insurance Agency. (2026). NDIS Pricing Arrangements and Price Limits 2026–27. https://www.ndis.gov.au/media/8703/download (accessed 3 November 2026).
  6. National Disability Insurance Agency. (n.d.). Our Guideline – Behaviour support [Confirm: exact page title]. https://www.ndis.gov.au/media/8508/download (accessed 3 November 2026).
  7. NDIS Quality and Safeguards Commission. (n.d.). Find an NDIS behaviour support practitioner. https://www.ndiscommission.gov.au/rules-and-standards/behaviour-support-and-restrictive-practices/find-ndis-behaviour-support (accessed 3 November 2026).

Talk to our PBS team

A functional behaviour assessment is one part of our positive behaviour support service. The PBS page covers the rest, including fees and who you might work with.

Positive behaviour support

Written by Trevor Keen, Founder and Physiotherapist [Confirm: byline author for this page]. Clinically reviewed by [Confirm: reviewer — Rowena Cornish or Jess Valerio, shown with NDIS Commission suitability].

Last reviewed 3 November 2026. How we write our pages

General information only. Speak with your GP or one of our team about your situation.

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