Functional Behavior Assessment: Steps, Example and Consent Rules

Estimated reading time: 15 minutes

A functional behavior assessment (FBA) is a process for finding out why a student engages in a behavior that interferes with learning: what triggers it, what keeps it going and what need it meets, so that a team can build a plan around that need. IDEA calls it a “functional behavioral assessment” and requires one in some disciplinary situations. This guide covers when an FBA is required, whether it needs parental consent, the steps, the four common functions of behavior, an example with an ABC table and a hypothesis statement, a template outline and who conducts it. It describes federal and state rules, not legal advice: check your state’s rules and consult district counsel.

Executive Summary

In 2023-24, students served under IDEA were 15% of K-12 enrollment but 24% of students with an in-school suspension and 27% of those with an out-of-school suspension, according to the Office for Civil Rights. In listening sessions held by the Department of Education, stakeholders said FBAs are most typically conducted in response to safety-related behaviors or after disciplinary action; the Department’s November 2024 guidance urges schools to use them more often, including for behaviors that are not safety-related.

The method has a research base. The National Clearinghouse on Autism Evidence and Practice (NCAEP) lists FBA among 28 evidence-based practices for autistic children and youth, supported by 21 studies.

What Is a Functional Behavior Assessment?

A functional behavior assessment is a systematic process for determining why a student engages in a behavior that interferes with learning, by identifying the events that trigger and maintain it, so that the team can design positive supports that address its function.

The IRIS Center at Vanderbilt University puts it simply: educators ask not only “What does the student do?” but “Why does the student do that?” Neither IDEA nor the Elementary and Secondary Education Act defines an FBA, the Department’s 2024 FBA guidance notes. Some states do. New York requires the identification of the problem behavior, its definition in concrete terms, the contextual factors that contribute to it and a hypothesis about the conditions under which it occurs and the consequences that maintain it (8 NYCRR 200.1(r)). Virginia says an FBA may include a review of existing data or new testing as determined by the IEP team (8VAC20-81-10).

When Does IDEA Require a Functional Behavior Assessment?

Outside these situations, an FBA is a matter of good practice. IRIS frames the decision with three questions: for whom (students with severe or chronic behavior that earlier supports did not resolve; an IEP or Section 504 plan is not a prerequisite), for which behaviors (those with a significant impact on learning or safety), and when (after classroom management and low-intensity strategies have not worked). A student whose behavior threatens anyone’s safety should be referred immediately. The disciplinary procedure itself is covered in our guide to manifestation determination.

Does an FBA Need Parental Consent?

It depends on why the FBA is done. The Department’s November 2024 guidance, issued by the Office of Special Education and Rehabilitative Services (OSERS) and the Office of Elementary and Secondary Education, sets out the Department’s position:

In the Department’s view, when an FBA is part of an evaluation, a parent who disagrees with it may request an independent educational evaluation at public expense (34 CFR 300.502(b)). The Second Circuit held in D.S. v. Trumbull Board of Education (2020) that an FBA is not an evaluation that triggers that right; the Department treats the decision as controlling in that circuit but disagrees to the extent it suggests an FBA cannot be part of an evaluation. States may require consent in more situations, as IRIS notes, and Oregon runs its 45-day clock from parental consent. Proposing an evaluation also calls for prior written notice (34 CFR 300.503). Settle your district’s consent practice with counsel.

How to Conduct a Functional Behavior Assessment

The 2024 module on FBA from AFIRM (Autism Focused Intervention Resources and Modules, University of North Carolina) and the IRIS Center describe the same core sequence.

1. Form the team and plan. Include everyone who has observed the behavior and the family; address behaviors that create safety concerns first; plan to collect data where the behavior occurs most often and where it does not (AFIRM).
2. Define the behavior. Write an operational definition that is observable, measurable and actively stated, so clear that “anyone could walk into the classroom without knowledge of the student and identify whether the behavior occurs” (IRIS), with examples and nonexamples.
3. Gather indirect data. Review records, conduct structured interviews of about 10 to 30 minutes with staff, the family and the student, using an interpreter when needed, and use rating scales. IRIS cautions that indirect assessments alone do not identify the function, and New York bars an FBA based solely on the student’s history of problem behavior (8 NYCRR 200.22(a)(2)).
4. Observe directly. An objective observer records antecedent-behavior-consequence (ABC) data across different days and contexts, noting setting events such as a conflict before school. A scatterplot shows when the behavior happens and when it does not. Formats are in our IEP data collection sheets.
5. Write the hypothesis. IRIS’s sequence: look for skill deficits, summarize the context, identify setting events, then patterns in antecedents and consequences, then name the function. AFIRM adds a refined description of the behavior itself.
6. Test the hypothesis. AFIRM describes changing the setting or activity in a way that should make the behavior more likely, over several days or weeks; NCAEP notes the conditions are sometimes tested systematically through a functional analysis. Plan any test with a qualified behavior specialist and clear stop rules when safety is at stake.
7. Use the results. New York requires an FBA detailed enough to form the basis of a plan that addresses antecedents, reinforcing consequences, alternative skills and the student’s reinforcement preferences (8 NYCRR 200.22(a)(3)).

The Four Functions of Behavior

IRIS groups functions into four categories; the 2024 guidance and AFIRM simplify them to two: to obtain something, or to escape or avoid something.

IRIS calls automatic functions very rare and advises consulting other professionals, such as behavior analysts, when one is suspected.

Functional Behavior Assessment Example

The example below is original, about a fictional student, and written for this guide. Adapt the definitions and data methods to your district’s forms.

Student: Sam, grade 4, IEP for a specific learning disability in math. Behavior: leaving the classroom, defined as crossing the doorway without adult permission; leaving with a pass or with the class does not count. Indirect data: six referrals for leaving since September, all between 10:00 and 11:00; his teacher reports it starts when independent math begins; his parent reports refusals of math homework.

Pattern: leaving occurs only when Sam must do math alone, never in small groups or science, and each time the task ends or is postponed.

Hypothesis statement: During independent math practice, when Sam is given a worksheet or a timed task to complete alone, he leaves the classroom, which ends or postpones the task. The team hypothesizes that leaving serves to escape independent math work; it is more likely on days with a timed fact check.

Test: for one week, with an adult near the door, the teacher alternates independent worksheets with the same problems done with a partner. Sam leaves on 3 of 3 independent days and 0 of 2 partner days, which supports the hypothesis. The plan that follows teaches Sam to ask for help or a short break, splits the worksheet into short sets and reinforces each completed set; see our behavior intervention plan guide.

Functional Behavior Assessment Template

1. Student, dates and team, including the parent.
2. Reason for the FBA and consent status.
3. Operational definition with examples and nonexamples.
4. Baseline: frequency, duration, intensity or latency, by setting and time.
5. Indirect data: records reviewed, interviews, rating scales.
6. Direct data: ABC records and scatterplot, with dates and observers.
7. Patterns: where and when it occurs and does not, setting events, skill deficits.
8. Hypothesis statement naming the function.
9. Hypothesis test and result.
10. Recommendations for the behavior plan and the IEP.

Who Conducts an FBA?

IDEA names no profession. OSEP’s 2022 Q&A on discipline says districts must ensure that personnel who conduct FBAs are appropriately and adequately prepared, and that assessments are administered by trained and knowledgeable personnel (34 CFR 300.304(c)(1)(iv)). The 2024 guidance adds that the professionals collecting data should engage parents and students. IRIS suggests that an objective person, such as a school psychologist, another educator or a behavior analyst, conduct the observations, and under its serious-injury rule Oregon requires the FBA behind a plan to be conducted by a person with training or experience in FBAs.

From the FBA to the Behavior Plan

AFIRM’s last step is a plan that prevents the behavior, teaches or increases the replacement behavior, and increases learning opportunities and social engagement. That plan, and how to review it, is covered in our behavior intervention plan guide; the skill the student will learn becomes a measurable goal, with examples in behavior IEP goals.

Funding and Staffing

The 2024 guidance lists IDEA Part B among funds that can support FBAs, positive behavioral supports and staff training, and early intervening services may pay for behavioral evaluations for K-12 students not yet identified (34 CFR 300.226). Trained observers are the scarcer resource: 45 states reported special education teacher shortages in 2024-25 (Learning Policy Institute, 2026).

Common Mistakes District Leaders Make

1. Waiting for a removal. An FBA after a suspension starts late.
2. Accepting labels as definitions. “Defiant” cannot be counted.
3. Relying on interviews alone. Indirect data do not identify the function.
4. Recycling the discipline history. New York forbids an FBA based solely on it.
5. Observing only when the behavior happens. Non-occurrence shows what already works.
6. Writing feelings into the hypothesis. IRIS warns against phrases such as “because he is embarrassed.”
7. Skipping the consent question, which depends on the purpose of the FBA.
8. Filing the FBA without a plan.

Questions District Leaders Should Ask

• How many FBAs did we complete this year, and how many began before any disciplinary removal?
• What share include direct observation across at least two settings?
• Who on each campus is trained to conduct an FBA, and who covers when they are absent?
• How many FBAs led to a behavior plan within a month?

Frequently Asked Questions

What is the purpose of a functional behavior assessment?

To find out why a behavior happens so the team can address its cause instead of reacting to it. OSEP describes an FBA as used to understand the function and purpose of a student’s interfering behavior and the factors behind its occurrence and non-occurrence, in order to develop positive behavioral interventions and supports. The result is a hypothesis about the function that guides the behavior intervention plan.

When is a functional behavior assessment required?

IDEA requires an FBA when the team finds that conduct behind a disciplinary change of placement was a manifestation of the student’s disability, unless one was done before the behavior (34 CFR 300.530(f)), and “as appropriate” after other long removals. States add triggers: New York includes an FBA in the initial evaluation of a student whose behavior impedes learning, and Oregon requires one after behavior that created an imminent risk of serious bodily injury.

Who can conduct a functional behavior assessment?

IDEA does not name a profession. Districts must ensure that the people who conduct FBAs are appropriately trained, and assessments must be administered by trained and knowledgeable personnel. In the Department’s 2024 example, a counselor, special and general education teachers and a paraprofessional collected the data; IRIS suggests an objective observer, such as a school psychologist or a behavior analyst. Some states, such as Oregon, require a person with FBA training or experience.

How long does a functional behavior assessment take?

IDEA sets no deadline for an FBA as such. When it is part of an initial evaluation, the 60-day federal timeline, or the state’s own, runs from consent (34 CFR 300.301(c)); Oregon allows 45 school days under its serious-injury rule. Individual pieces are short: IRIS puts structured interviews at about 10 to 30 minutes, but observations across settings and a test of the hypothesis can take several weeks.

Are functional analysis and functional assessment the same?

No. A functional behavior assessment is the whole process: defining the behavior, interviews, observation and a hypothesis. A functional analysis is one way to test that hypothesis by systematically arranging the conditions around the behavior; NCAEP notes that antecedents and consequences are “sometimes systematically tested through a functional analysis.” Because a test may provoke the behavior, plan it with a qualified behavior specialist.

Can AI help summarize FBA data?

An AI tool can sort de-identified ABC notes by setting or time, or turn a team’s patterns into a first draft of a plain-language summary for a family meeting. It cannot observe the student, judge which consequence maintains the behavior or replace the team’s hypothesis. Strip names and identifying details, and use only district-approved tools. The ChatGPT for teachers guide covers safe prompting.

Related Resources

• Behavior Intervention Plan
• Functional Communication Training
• Behavior IEP Goals
• Manifestation Determination
• IEP Data Collection Sheets
• Special Education Evaluation
• Prior Written Notice Examples
• Restraint and Seclusion in Schools

Conclusion

A good functional behavior assessment replaces a label with a definition, opinions with observations, and a guess with a tested hypothesis. Districts that settle the consent question by purpose, train enough observers and act before a removal turn FBAs into plans that address the reason a behavior happens.

Sources: 34 CFR 300.530, Authority of school personnel; 34 CFR 300.300, Parental consent; OSEP, Questions and Answers: Addressing the Needs of Children with Disabilities and IDEA’s Discipline Provisions (July 19, 2022); OSERS and OESE, Using Functional Behavioral Assessments to Create Supportive Learning Environments (November 2024); IRIS Center, Functional Behavioral Assessment (Elementary): Identifying the Reasons for Student Behavior; Sam and AFIRM Team, Functional Behavior Assessment, Updated (2024); Steinbrenner et al., Evidence-Based Practices for Children, Youth, and Young Adults with Autism, NCAEP (2020); 8 NYCRR 200.22, Program standards for behavioral interventions; OAR 581-015-2181, Functional Behavioral Assessments; OCR, 2023-24 A First Look: The Civil Rights Data Collection (September 2026). Other regulations are linked where they are cited.

Join the 2027 Special Education Pilot

An FBA usually ends with a skill the student must learn to use instead of the behavior, and learning it takes far more practice turns than a weekly session can offer. Telo AI is being adapted for students with IEPs: patient, 1-on-1 practice aligned to each student’s IEP goals, including social-emotional learning. We are inviting districts to shape it with us in a 2027 pilot.

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