Let’s Talk About: Intellectual Disability Eligibility

Only 6 percent of students served under IDEA are eligible under the Intellectual Disability umbrella. This category is extremely specific in definition, eligibility, and subgroups.  

The IDEA defines Intellectual Disability (ID) in section 34 C.F.R § 300.8(c)(6) as “significantly subaverage general intellectual functioning which exists concurrently with deficits in adaptive behavior that adversely affects educational performance and originates before age 18.” However, there are caveats; the ID category does not include conditions in which intellectual disability can be a symptom, such as sensory or physical impairment, traumatic brain injury, ASD, and severe multiple impairments. Also, cultural influences or a history of inconsistent and/or inadequate educational programming does not qualify a child as intellectually disabled.

“Significant subaverage general intellectual functioning” is defined as an IQ score of 70 or below. A qualified psychological examiner must administer more than one formal measure of intelligence to make the final determination. But remember, when these test results are interpreted, all factors that may affect test performance must be considered. These factors include socioeconomic status, native language, and cultural background, as well as disabilities in communication, sensory, or motor areas. 

The definition of ID includes that second requirement: the child must also have deficits in adaptive behavior. Deficits in adaptive behavior are significant limitations in a child’s effectiveness in meeting the standards of maturation, learning, personal independence or social responsibility, and especially school performance.  

When there are deficits in both intellectual functioning and adaptive behavior, the child can be classified as having an intellectual disability. There are four levels of intellectual disability. 

1. Mild intellectual disability (MID or MiID): Intellectual functioning ranging between 70-55.

2. Moderate intellectual disability (MOID): Intellectual functioning ranging from 55-40.

3. Severe intellectual disability (SID): Intellectual functioning between 40-25.

4. Profound intellectual disability (PID): Intellectual functioning between 25 and lower.

Consider this situation: a child has just moved to the US from a third-world country and enrolled in public school. The child never had the opportunity to attend school in their country. The child does not speak English. Then, the school completes testing with that child. The scores come out in the significantly subaverage range. Does that mean the child has an intellectual disability? Maybe. Is it possible the child scored so low because they have never been exposed to education, curriculum, testing, print materials, etc.???  Definitely.  

What about a situation where a child and his family have been homeless for several years? The family bounced around between shelters and extended-stay hotels. They have finally gotten stable, and the child is enrolled in school. The school’s testing shows he falls in the MiID range and is immature in social skills and personal independence. Does the child have an intellectual disability?  Possibly. Could the child's scores be low because he has no consistent education and economic disadvantages?  Likely. 

This is why the ID category is so specific and exclusive. If a lack of appropriate instruction in reading, math, and writing; limited English proficiency; visual, hearing, or motor disabilities; emotional disturbances; cultural factors; environmental or economic disadvantage; or an atypical educational history are the predominant factors causing low scores for the child, they cannot be determined to be a child with an Intellectual Disability.