Understanding the eligibility category that is designated on your child's IEP is important because it enables you to come from the same "starting place" as an IEP team. With so many categories and "labels," it can definitely be confusing, particularly for parents who are new to the "system." For preschool aged students, understanding the longer term relevance of the category designated is also important.
The IDEA allows for eligibility under the category of "Developmental Delay," which is a unique category with different rules than the other categories, and only applies to a particular age group.
Developmental Delay as an eligibility category is an option.
States can choose to recognize DD as an eligibility and create guidelines for determining eligibility under this category. Then, if the state has set forth DD as an option, individual school districts can choose whether to adopt DD as a category. The state cannot force the District to adopt DD for eligibility purposes, but if the state itself doesn't adopt DD, then the school districts are not allowed to use that category. (The 1997 amendments of the IDEA changed the provisions related to Developmental Delay to make the adoption of this category in the discretion of both the SEA and the LEA, rather than solely in the discretion of the SEA). If the state chooses to adopt DD as an eligibility category, then a school district that chooses to use this category must apply the state's definition of DD and the state's determination of age range. A district cannot deviate from the definition of developmental delay or the age range adopted by the state. 34 C.F.R. section 300.111(b)(3).
Definition of Developmental Delay
The IDEA: Developmental delay includes a student who is experiencing developmental delays as defined by the state and as measured by appropriate diagnostic instruments and procedures, in one or more of the following areas: physical development, cognitive development, communication development, social or emotional development, or adaptive development. 34 C.F.R. 300.8(b)(1).
Of course, as stated above, the states have the power to define "developmental delay," including adding details to the definition above, or setting the specific date range that is covered by this category. Included below is a list of the details / criteria from California's definition of DD, since that is the one I am familiar with, as well as a few others I've been able to locate.
Legal Citation: Title 5, California Code of Regulations, section 3031
Age Range: through age 4 years and nine months
Criteria: There are three ways to meet the criteria. (1) Child must be functioning at or below 50% of his / her chronological age level in any one of the identified skill areas (gross or fine motor, receptive or expressive language, social or emotional development, cognitive development, visual development); or (2) Child must be functioning between 51% and 75% of his / her chronological age in any two of the identified skill areas (see above); or (3) Child has a disabling medical condition or congenital syndrome which the team determines has a high predictability of requiring intensive special education services (i.e. "at risk" category).
Legal Citation: COMAR 13A.05.01.03B(69)
Age Range: school districts have the option of utilizing the DD category for students age 3 to 5, or for students up to any age not exceeding 9.
Criteria: There are three ways to meet the criteria - (1) Child has 25% or greater delay in adaptive, cognitive, communicative, emotional, physical or social development as measured and verified by appropriate diagnostic instruments and procedures; or (2) Child has atypical development or behavior, which is demonstrated by abnormal quality of performance and function in one or more of the specified areas, and which interferes with current development and is likely to result in subsequent delay; or (3) Child has a diagnosed physical or mental condition (elsewhere defined in the statute) which has a high probability of resulting in a developmental delay, including students with sensory impairments inborn errors of metabolism, microcephaly, fetal alcohol syndrome, epilepsy, Down Syndrome, and other chromosomal abnormalities.
Legal Citation: Wisconsin Administrative Code, PI 11.02 (11)
Age: through age 5 or "below the age for compulsory education"
Criteria: (1) First, all other suspected areas of eligibility must be ruled out; (2) Child must demonstrate delays in development that significantly challenge the child in two or more of five specifically identified "major life activities" including: physical activity in gross motor skills; cognitive activities; communication; emotional activities; and adaptive activities; and (3) These delays must be documented via quantitative and qualitative measures.
What's Important to Know about the Developmental Delay Category
It's important to realize that based on the IDEA and your state's regulations, there may be a "cut off date" for eligibility under the DD category. Some school districts interpret this to mean that a child is to be automatically exited from special education at that age. This isn't an accurate interpretation or appropriate approach. Rather, if a child's sole category of eligibility has been under DD, then the school district should reevaluate before the "cut off age" in order to determine if the child meets the criteria in another area. Remember - school districts are obligated to assess a child in all areas of suspected disability, so the reevaluation should be sufficient to identify other possible areas in which the child may have needs that require special education and related services.