Question 1

What is this calculator for?

Accepted Answer

This is a free, client-side eligibility screener for Early Intervention (IDEA Part C, ages 0 - 36 months) and the IDEA Part B Section 619 preschool special-education programme (ages 3 - 5). Enter the child's chronological age and a single performance value (percent delay, standard score on a norm-referenced developmental test, or a developmental age in months) and the tool checks the child against the four canonical state eligibility rule families published in the Early Childhood Technical Assistance Center (ECTA 2015) state summary. The result panel returns Meets / Borderline / Does not meet for each rule along with the margin from the published cut. Use the result to anchor a referral conversation with the state Part C lead agency or with the local school district child-find team — every state has its own published rule and the tool surfaces the four canonical cuts so the clinician can match the child's performance to the locally applicable rule. The tool is NOT a state-specific eligibility determination — always confirm the actual eligibility decision with the state Part C lead agency.

Question 2

What are the four canonical Part C eligibility cut families?

Accepted Answer

Per Shackelford (2006) NECTAC Notes 21 and the Early Childhood Technical Assistance Center 2015 state summary, U.S. Part C state eligibility cuts cluster into four families. (1) 25 % delay in one developmental domain (the most permissive cut, used in roughly a third of states). (2) 33 % delay in one domain or 25 % delay in two or more domains (the modal U.S. cut and the most common state-level rule on the ECTA 2015 summary). (3) 50 % delay in one domain or 25 % in two or more domains (used in roughly a sixth of U.S. states and territories). (4) Standard-deviation cuts: 1.5 SD below the mean (standard score $\leq$ 78 on a test with mean 100 and SD 15) and 2.0 SD below the mean (standard score $\leq$ 70). On top of these quantitative cuts every state must offer (a) categorical eligibility for diagnosed conditions with a high probability of resulting in developmental delay (Down syndrome, fetal alcohol syndrome, significant prematurity, hearing loss, vision loss, lead poisoning) and (b) eligibility on informed clinical opinion (34 CFR 303.321(a)(3)(ii)) when standardised test data under-represent the child's true developmental risk.

Question 3

How do I enter the child's performance value?

Accepted Answer

Pick the input mode that matches the data you have on the evaluation report. (1) "Percent delay" — enter the published percent delay directly as a number (e.g. 33 for a 33 % delay). This is the most common output from the developmental evaluation report. (2) "Standard score" — enter the standard score from a norm-referenced test (Bayley-4, BDI-3, MSEL, REEL-4, PLS-5, CELF-Preschool-3, etc.) on the standard mean-100 SD-15 metric. The tool converts the score to a z-score and checks the SD cuts. (3) "Developmental age" — enter the age-equivalent in months reported by a developmental test and the tool computes the percent delay using the published Part C formula: percent delay = (chronological age − developmental age) / chronological age. A 24-month-old performing at 18 months has a 25 % delay.

Question 4

Why does the tool show four rules side-by-side instead of one?

Accepted Answer

Because state Part C eligibility rules vary widely and a single national cut does not exist. Per the ECTA 2015 state summary, roughly a third of U.S. states use the 25 % rule, the modal U.S. cut is the 33 % rule (used in roughly a third of states), a sixth of states use the 50 % cut, and a separate set of states use 1.5 SD or 2.0 SD norm-referenced cuts. Showing all four cuts side-by-side lets the clinician see which rules the child meets and match the result to the locally applicable rule. Borderline outcomes flag children whose performance falls within measurement error of the cut so the clinician knows when a re-test or an informed-clinical-opinion route is warranted.

Question 5

What is "informed clinical opinion" and when does it apply?

Accepted Answer

Informed clinical opinion (ICO) is a federally mandated eligibility route under 34 CFR 303.321(a)(3)(ii) — every U.S. state Part C programme must accept ICO as an eligibility category alongside the quantitative cut. ICO applies when standardised test data under-represent the child's true developmental risk: a child who is too young, too dysregulated, too ill, or too unfamiliar with the examiner to be tested validly; a child with a complex medical history; a child with strong family-history risk; or a child whose performance varies widely between settings. ICO does not require a percent delay or a standard score below the cut — it relies on the qualitative judgment of the multi-disciplinary evaluation team. Document the ICO basis explicitly in the eligibility paperwork: the team's review of the medical record, the parent interview, the structured observation, and the developmental history all count.

Question 6

What is "categorical eligibility" for diagnosed conditions?

Accepted Answer

A child with a diagnosed condition with a high probability of resulting in developmental delay is categorically eligible for Part C — no quantitative test or percent-delay cut is required. The federal IDEA Part C regulation (34 CFR 303.21) lists examples: chromosomal abnormalities (Down syndrome, Trisomy 18, Fragile X), genetic or congenital disorders (cerebral palsy, spina bifida), congenital infections, sensory impairments (severe visual or hearing loss), inborn errors of metabolism, FAS / FASD, significant prematurity (typically born at < 32 weeks gestation or < 1500 g), severe attachment disorders, and exposure to lead. Each state publishes its own list of categorically eligible conditions on top of the federal floor — the ECTA Center keeps a state-by-state comparison. A child with a diagnosed condition is referred to Part C immediately and the eligibility paperwork is processed without a developmental evaluation as the gating step.

Question 7

What's the difference between Part C and Part B Section 619?

Accepted Answer

Both are sub-parts of the Individuals with Disabilities Education Act (IDEA) and both are federal programmes administered through the states. IDEA Part C — Infants and Toddlers with Disabilities — covers children from birth through age 3 (the day before the third birthday). Part C services are delivered through the state Early Intervention programme (the state lead agency varies by state — sometimes the Department of Health, sometimes Education, sometimes Disabilities). Services are free, no parent referral is required, the evaluation is at home or in a community setting, and the family receives an Individualised Family Service Plan (IFSP). IDEA Part B Section 619 — Preschool Grants — covers children ages 3 through 5 (until kindergarten entry). Part B Section 619 services are delivered through the local school district child-find office and the school district special-education team. Services are still free, the evaluation is done by the school district, and the child receives an Individualised Education Programme (IEP) instead of an IFSP. Children transitioning from Part C to Part B Section 619 around their third birthday should be referred to the school district child-find team at least 90 days before the transition (the federal "transition meeting" requirement).

Question 8

How do I make the actual referral?

Accepted Answer

For a child under age 3: call the state Early Intervention programme directly. Every U.S. state has an EI office and the phone number is on the CDC "Learn the Signs. Act Early." website (https://www.cdc.gov/ncbddd/actearly/parents/states.html). A paediatrician referral is helpful but is NOT required — federal law guarantees that any caregiver, family member, social worker, or community member can make the referral. The EI evaluator will come to the home within 45 days of the referral and will run a multi-domain developmental evaluation. For a child age 3 - 5: contact the local school district child-find office. Every U.S. school district has one and it is legally required to evaluate any child age 3+ with a suspected delay regardless of whether the child attends a public preschool. The evaluation is done by the school-district special-education team, services are free, and the child receives an IEP at the preschool. For both pathways: pair the referral with a paediatric audiology hearing evaluation because mild fluctuating conductive hearing loss from otitis media is one of the most common reversible causes of speech-language delay.

Question 9

Is the tool a substitute for a Part C evaluation?

Accepted Answer

No. The tool is a quick eligibility screener that maps a single performance value to the canonical state cut families — it is not a standardised developmental evaluation and it does not produce an IFSP or an IEP. A Part C eligibility decision requires a multi-domain developmental evaluation by a qualified team using a state-approved instrument (Bayley-4, BDI-3, MSEL, etc.), parent interview, structured observation, and review of the medical record. Use this tool to decide whether to make the referral, not to make the eligibility determination itself.

Question 10

Is the tool appropriate for bilingual children?

Accepted Answer

Yes, with caveats. Bilingual children must be evaluated in both languages or in their dominant home language under 34 CFR 303.321(a)(5) and 34 CFR 300.304(c)(1)(ii). Standardised norm-referenced developmental tests with standard scores assume monolingual American English performance and will systematically under-estimate bilingual children — entering an English-only standard score for a Spanish-dominant 2-year-old is one of the most common false-positive eligibility flags in U.S. paediatric primary care. Use the developmental-age input mode with a bilingual or dialect-aware evaluator, document the bilingual exposure in the eligibility paperwork, and rely on informed clinical opinion when the standardised data under-represent the child's true competence.

Question 11

Is my data private?

Accepted Answer

Yes. The calculator runs entirely in your browser. Nothing is sent to a server, nothing is saved, and the values you enter are gone the moment you close the tab. The tool is safe to use at the point of care, in the home visit, in the well-child visit, or by a parent at home.

Early Intervention Eligibility Calculator

Check the child against the four canonical Part C eligibility cuts

Skip the manual count with ConductSpeech

Why Early Intervention Matters

The Percent Delay Formula

The Standard Deviation Cuts (1.5 SD and 2.0 SD)

Diagnosed Conditions and Informed Clinical Opinion

Frequently Asked Questions

Next Steps

Speech-Language Milestones Checker — pair the eligibility verdict with the ASHA + CDC (Zubler 2022) age-banded receptive and expressive milestones

Reading Grade Level Analyzer — check the parent-facing eligibility letter and intake handout against the AMA / NIH / CDC grade-6 readability target

MLU Calculator — compute Mean Length of Utterance in morphemes from a 50-utterance language sample for a child already producing two-word combinations

SUGAR Norms Lookup — look up SUGAR (Pavelko & Owens 2017) normative MLU, TNW, CPS, and MLUL values for ages 3;0 - 7;11

Speech Sound Development Chart — cross-check expressive speech-sound milestones against the Crowe & McLeod (2020) age-of-acquisition norms

Speech Intelligibility by Age Calculator — anchor an observed unfamiliar-listener intelligibility percent against the Coplan & Gleason / Flipsen / Hustad age bands

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