IEP BasicsIllinois

The IEP Triennial Reevaluation: What to Expect and How to Use It

How this applies in Illinois

11 min readMarch 6, 2026

By Adam Matossian · Founder of IEP Says. Father, advocate, and builder — helping parents understand and navigate their child's IEP.

Quick Answer

The triennial reevaluation is a federally required comprehensive evaluation of your child's disability and educational needs that must occur at least every three years. Schools can propose to skip new testing if the team — including you — agrees existing data is sufficient. You are never required to waive new testing, and you can request an independent evaluation if you disagree with the results.

What Is the Triennial Reevaluation?

Every child who receives special education services must be reevaluated at least once every three years. This is the triennial reevaluation — sometimes called the "three-year evaluation" or simply "the triennial."

The legal authority is 34 CFR §300.303, which requires reevaluation to:

  • Determine whether the child continues to have a disability
  • Determine the child's current educational needs
  • Determine whether the child continues to need special education and related services
  • Determine whether any additions or modifications to the IEP are needed

The triennial is not the same as the annual IEP review. The annual review looks at goals and progress. The triennial goes deeper — it re-examines the foundation: the disability itself, how it affects the child today, and what the data says about the child's needs.

Important: Reevaluations must occur at least once every three years, but they cannot occur more than once per year unless both the parent and the school agree otherwise.

What Gets Evaluated?

The scope of the triennial evaluation must be broad enough to cover all areas related to the child's suspected disability. At minimum, the evaluation typically addresses:

  • Cognitive functioning — IQ-type assessments measuring reasoning and processing
  • Academic achievement — standardized tests of reading, math, writing
  • Social-emotional and behavioral functioning — rating scales, observations, interview data
  • Adaptive behavior — daily living skills, self-management, independence
  • Communication and language — if communication is a concern or service area
  • Motor skills — if occupational or physical therapy is involved
  • Sensory functioning — vision and hearing screenings
  • Health history — medical information relevant to educational needs

For older students approaching 16 (or earlier in some states), the evaluation must also include a review of transition-related needs — career interests, vocational skills, and post-secondary goals.

Not every domain requires new formal testing. The IEP team first reviews existing data and determines where gaps exist. But the evaluation must be comprehensive enough to actually answer the question: what does this child need now?

Starting With Existing Data

Before any new testing is scheduled, federal law requires the IEP team to review existing evaluation data and consider:

  • Previous evaluation results on file
  • Current classroom-based assessments and observations
  • Information from teachers and related service providers
  • Information you provide as the parent

After this review, the team decides what additional data — if any — is needed. You will receive written notice of what assessments will be conducted and why. If you believe an important area is being overlooked, say so in writing before consent is given.

Parent tip: Write a letter to the evaluation team before testing begins. Include:

  • Your observations of changes in the past three years
  • Any private evaluations, medical diagnoses, or therapy reports you have
  • Any areas of concern the school has not yet assessed
  • Specific questions you want the evaluation to answer

Your input legally must be considered. Putting it in writing creates a record.

Your Rights in the Process

You have specific rights throughout the reevaluation process:

  • Informed consent: The school must get your written consent before conducting a reevaluation (unless the school can document that it tried and was unable to get a response from you). No evaluation may begin without your agreement.
  • Evaluation timeline: The school must complete the evaluation within 60 calendar days of receiving your consent, or within your state's established timeline if shorter.
  • Copy of the report: You are entitled to receive a written copy of the evaluation report before the IEP meeting where results are discussed.
  • IEP meeting to review results: The school must convene an IEP team meeting — with you — to review and interpret the results and determine whether eligibility continues and what changes (if any) are needed.
  • Right to an IEE: If you disagree with the evaluation, you may request an Independent Educational Evaluation at public expense. See our guide to IEEs.

If the school tries to hold the IEP meeting before you have received or had time to review the evaluation report, you can ask to reschedule. You are allowed to come prepared.

The Reevaluation Waiver

Under 34 CFR §300.303(b)(2), the reevaluation may be skipped if:

  1. Both the school and the parent agree that a reevaluation is unnecessary, AND
  2. The agreement is documented in writing

Schools sometimes propose waivers to save time and resources. You may also agree if recent private evaluations have provided thorough, current data.

However: you are never required to waive the evaluation. If you want comprehensive testing done — especially if you believe your child's needs have changed, or if you're concerned about whether the IEP is working — say no to the waiver.

Reasons you might decline the waiver:

  • Your child has received a new medical or psychiatric diagnosis
  • You believe the current IEP is not working and want data to support changes
  • The last evaluation was limited in scope
  • Your child has regressed significantly
  • You are considering a more restrictive or less restrictive placement and need updated data
  • Your child is approaching transition age and transition assessment is needed

Declining the waiver is your right. The school cannot retaliate, and it cannot interpret a waiver declination as a sign of conflict. Simply respond in writing: "We would like the reevaluation to proceed."

Requesting a Reevaluation Early

You do not have to wait three years. Under 34 CFR §300.303(a), a reevaluation may be conducted more frequently when:

  • Conditions warrant a reevaluation, OR
  • The child's parent or teacher requests one

The only restriction: the school may not conduct a reevaluation more than once per year unless both the parent and school agree it is warranted.

When to request an early reevaluation:

  • New diagnosis (autism, ADHD, anxiety, learning disability) that was not reflected in the previous evaluation
  • Significant regression in skills or functioning
  • Major transition (elementary to middle school, or middle to high school)
  • Dispute over services or placement that requires updated data
  • The current IEP goals don't seem connected to the child's actual profile
  • A significant change in medication or medical status
  • A private therapist or provider raises concerns not captured in school data

To request a reevaluation, send a written request — email is fine, with a follow-up in the mail if important — to your child's special education case manager and the building principal. State clearly that you are requesting an evaluation under 34 CFR §300.303 and explain why. The school must respond in a reasonable timeframe and either begin the evaluation process or provide a written explanation of why it is declining.

If the school declines and you disagree, you can file a state complaint or request due process.

How to Use the Results

The real power of the triennial evaluation is what you do with it. The evaluation report is not just a document — it is a roadmap for what your child needs. Here is how to use it effectively:

Before the IEP meeting:

  • Read the full report before the meeting. Don't let it be reviewed for the first time in the room.
  • Note every area of weakness flagged by the evaluator. These are potential goal areas.
  • Bring a written list of questions — e.g., "The report says her processing speed is in the 8th percentile. How is this addressed in the current IEP?"
  • Ask the evaluator to explain what each score means in practical terms if the jargon is confusing.

At the IEP meeting:

  • Request that the evaluation results be directly linked to proposed IEP goals and services. If there is a gap in the profile that isn't addressed by a goal, ask why.
  • Ask: "Based on these results, what services are recommended?"
  • Ask: "Is the current placement appropriate given these scores?"
  • If the evaluation identifies a new area of need (e.g., pragmatic language, executive function), ask for a new goal or related service to address it.

After the meeting:

  • If you disagree with the eligibility determination, placement decision, or goals that resulted from the evaluation, you may request an IEE or file for due process.
  • Keep the evaluation report with your child's IEP records. It is a legal document.
  • Use the baseline scores as comparison data at the next triennial — this shows whether the IEP has been working.

What to Watch For

Not all triennial evaluations are conducted with equal care. Common concerns to be aware of:

  • Narrow evaluation scope: The school only tests academic achievement when the child has significant social-emotional or adaptive functioning concerns. Ask for a broader assessment.
  • Outdated tests: Ask what edition of each instrument was used. Outdated standardization norms can inflate or depress scores.
  • Missing domains: If your child receives speech therapy, there should be speech-language assessment data. If they receive OT, there should be motor/sensory data. A missing domain means the IEP cannot be properly calibrated.
  • Rushed eligibility findings: A school saying "we'll just continue with the same eligibility" without reviewing the evaluation data carefully may be cutting corners.
  • Pressure to sign at the meeting: You are never required to sign the IEP or agree to eligibility determinations the same day. Take the time you need to review the report and consult with an advocate if needed.
  • Evaluator conflicts: The evaluator works for the district. This doesn't mean the evaluation is biased — most are conducted professionally — but it is one reason why you have the right to an IEE if you disagree.

Your bottom line: The triennial reevaluation is one of the most important leverage points in the IEP process. A good evaluation, used well, can unlock services, placements, and goals that better match your child's actual profile. Show up prepared, read the report beforehand, and use the data to ask specific, grounded questions.

Illinois — State-Specific Guidance

Illinois follows the federal IDEA framework

The guidance in this article is accurate for Illinois parents. Below is how Illinois implements the relevant federal requirements.

Verified Mar 2026

Evaluation in Illinois

Illinois evaluation procedures are governed by 105 ILCS 5/14-8.02 and 23 IAC 226.110 and 34 CFR 300.303. Any concerned person — including parents, school personnel, community agencies, or state employees — may refer a child suspected of having a disability for evaluation (23 IAC 226.100). Within 14 school days of receiving a referral, the district must determine whether an evaluation is warranted and, if so, issue a domain review proposing which areas to assess (23 IAC 226.110(a)). Before the case study evaluation begins, the district must determine the child's primary home language, cultural identification, and mode of communication (105 ILCS 5/14-8.02(b)). All assessments must be selected and administered so as not to be racially, culturally, linguistically, or sexually discriminatory, and must be provided in the child's native language or mode of communication (23 IAC 226.110(b); 34 CFR 300.304). The 60-school-day timeline begins when the parent signs the domain review form consenting to the proposed assessments (23 IAC 226.110(d)). If fewer than 60 school days remain in the school year, the eligibility determination and IEP must be completed before the first day of the following school year. Evaluations must use technically sound instruments validated for their intended purpose, administered by trained and knowledgeable personnel according to publisher instructions (23 IAC 226.110(c)). Nonstandard administration conditions must be documented. The evaluation must assess all areas related to the suspected disability, including cognitive, behavioral, physical, and developmental factors (23 IAC 226.110(e)). Reevaluations must occur at least every three years (triennial) but not more than once per year unless the parent and district agree otherwise (34 CFR 300.303). Additional procedures apply for students suspected of having a specific learning disability (23 IAC 226.130) or intellectual disability (23 IAC 226.135).

Key Requirements

  • Any concerned person may refer a child for evaluation, including parents, teachers, community agencies, or state employees (23 IAC 226.100)
  • District must determine within 14 school days of referral whether evaluation is warranted (23 IAC 226.110(a))
  • Domain review must identify assessment areas; parental consent on the domain review form starts the 60-school-day clock (23 IAC 226.110(d))
  • Assessments must be nondiscriminatory — racially, culturally, linguistically, and sexually — and administered in the child's native language (23 IAC 226.110(b); 34 CFR 300.304)
  • Tests must be technically sound, validated for intended purpose, and administered per publisher instructions by qualified personnel (23 IAC 226.110(c))
  • Evaluation must assess all areas related to the suspected disability (23 IAC 226.110(e))
  • Reevaluation at least every 3 years (triennial), not more than once annually unless parent and district agree (34 CFR 300.303)
  • Additional procedures required for SLD (23 IAC 226.130) and intellectual disability (23 IAC 226.135)

Timelines

  • 14 school days from referral for district to determine whether evaluation is warranted (23 IAC 226.110(a))
  • 60 school days from parental consent on domain review to eligibility determination and IEP completion (105 ILCS 5/14-8.02(b); 23 IAC 226.110(d))
  • If fewer than 60 school days remain, eligibility and IEP must be completed before the first day of the next school year (23 IAC 226.110(d))
  • Reevaluation at least every 3 years (34 CFR 300.303)

Timelines & Deadlines in Illinois

Illinois special education law establishes numerous timelines governing the IEP process. For evaluations, the district must determine within 14 school days of receiving a referral whether an evaluation is warranted (23 IAC 226.110(a)). Once a parent signs consent on the domain review form, the district has 60 school days to complete the case study evaluation and eligibility determination (105 ILCS 5/14-8.02(b); 23 IAC 226.110(d)). If fewer than 60 school days remain in the school year, the eligibility determination and IEP must be completed before the first day of the following school year (23 IAC 226.110(d)). After eligibility is established, the IEP meeting must be held within 30 days (23 IAC 226.110(j)), and the approved IEP must be implemented within 10 school days (23 IAC 226.220). IEPs must be reviewed at least annually (34 CFR 300.324(b); 23 IAC 226.220). Reevaluations must occur at least every 3 years (triennial) but no more than once per year unless the parent and district agree (34 CFR 300.303). For meeting notification, written notice must be provided at least 10 days before the proposed meeting date (23 IAC 226.530(a)). For IEE requests, the district must respond within 5 days — either agreeing to fund or filing due process (105 ILCS 5/14-8.02), and must convene an IEP meeting within 10 days of receiving the IEE report (23 IAC 226.180(d)). For due process, complaints must be filed within 2 years of the alleged action; there is a 30-day resolution period, and the hearing must be completed within 45 days from the end of the resolution period (105 ILCS 5/14-8.02a; 34 CFR 300.515). Appeals to court must be filed within 120 days of the decision (105 ILCS 5/14-8.02a). Expedited hearings must be completed within 20 school days with a decision within 10 school days (23 IAC 226.655). State complaints must be resolved within 60 calendar days (23 IAC 226.570(c)). For home/hospital instruction, a minimum of 5 hours per week is required for students with medically necessary absences exceeding 2 consecutive weeks (23 IAC 226.300). Transition planning must begin at age 14.5 (105 ILCS 5/14-1.02).

Key Requirements

  • 14 school days from referral to determine if evaluation is warranted (23 IAC 226.110(a))
  • 60 school days from consent to eligibility determination and IEP completion (105 ILCS 5/14-8.02(b))
  • 30 days from eligibility to IEP meeting (23 IAC 226.110(j))
  • 10 school days from IEP approval to implementation (23 IAC 226.220)
  • Annual IEP review required (34 CFR 300.324(b))
  • Triennial reevaluation required (34 CFR 300.303)
  • 10 days written meeting notice (23 IAC 226.530(a))
  • 5 days for district to respond to IEE request (105 ILCS 5/14-8.02)
  • 10 days from IEE report to IEP meeting (23 IAC 226.180(d))
  • 120 days from decision to file civil action (105 ILCS 5/14-8.02a)

Timelines

  • 14 school days: referral to evaluation decision (23 IAC 226.110(a))
  • 60 school days: consent to eligibility determination and IEP (105 ILCS 5/14-8.02(b); 23 IAC 226.110(d))
  • If fewer than 60 school days remain: complete before first day of next school year (23 IAC 226.110(d))
  • 30 days: eligibility determination to IEP meeting (23 IAC 226.110(j))
  • 10 school days: IEP approval to implementation (23 IAC 226.220)
  • Annual: IEP review (34 CFR 300.324(b))
  • 3 years: triennial reevaluation (34 CFR 300.303)
  • 10 days: written meeting notification before proposed date (23 IAC 226.530(a))
  • 5 days: district response to IEE request (105 ILCS 5/14-8.02)
  • 10 days: IEE report to IEP meeting (23 IAC 226.180(d))
  • 2 years: statute of limitations for due process complaint (105 ILCS 5/14-8.02a)
  • 30 days: resolution period after due process filing (105 ILCS 5/14-8.02a)
  • 45 days: hearing completion from end of resolution period (34 CFR 300.515)
  • 120 days: from hearing decision to civil action (105 ILCS 5/14-8.02a)
  • 20 school days: expedited hearing (23 IAC 226.655)
  • 60 calendar days: state complaint resolution (23 IAC 226.570(c))
  • 1 year: lookback period for state complaints (23 IAC 226.570(b))
  • Age 14.5: transition planning begins (105 ILCS 5/14-1.02)
  • 5 hours/week minimum: home/hospital instruction (23 IAC 226.300)

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This article is provided for informational purposes only and does not constitute legal advice. For specific questions about your child's IEP, consult a qualified special education attorney or advocate.