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IDEA Category of Disability (Developmental Delay)
Description &Definition of developmental delay:
(1) 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; and
(2) Who, by reason thereof, needs special education and related services. [34 CFR §300.8(b)]
a) Children aged three through nine experiencing developmental delays. Child with a disability for children aged three through
nine (or any subset of that age range, including ages three through five), may, subject to the conditions described in
§300.111(b).
It’s a good idea to find out if your state has added details to this definition of developmental delay. States are allowed to do so, if they
choose. They also decide on the age range of children with whom the term may be used (3-5, 3-9, or any subset between 3-9).
It may be helpful to know that, under IDEA:
Your state may not require that your local school district also adopt and use the term developmental delay in working with
children.
If your local school district decides to use the term, it must use the same definition and age range as the state does.
Characteristics:
Skills such as taking a first step, smiling for the first time, and waving “bye bye” are called developmental milestones. Children reach
milestones in playing, learning, speaking, behaving, and moving (crawling, walking, etc.). A developmental delay is when your child
does not reach these milestones at the same time as other children the same age.
What are developmental milestones?
Developmental milestones are a set of functional skills or age-specific tasks that most children can do at a certain age range. Your
pediatrician uses milestones to help check how your child is developing. Although each milestone has an age level, the actual age
when a normally developing child reaches that milestone can very quite a bit. Every child is unique!

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Examples of Developmental Milestones:
Gross motor: using large groups of muscles to sit, stand, walk, run, etc., keeping balance, and changing positions.
Fine motor: using hands to be able to eat, draw, dress, play, write, and do many other things.
Language: speaking, using body language and gestures, communicating, and understanding what others say.
Cognitive: Thinking skills: including learning, understanding, problem-solving, reasoning, and remembering.
Social: Interacting with others, having relationships with family, friends, and teachers, cooperating, and responding to the
feelings of others.
If a developmental delay is not recognized early, children must wait to get the help they need. This can make it hard for them to learn
when they start school. In the United States, 17 percent of children have a developmental or behavioral disability. But, less than half of
children with problems are identified before starting school.
Additional Resources:
NICHCY Developmental Delay Resources:
The National Dissemination Center for Children with Disabilities (NICHCY)offers brief, but detailed fact sheets on Developmental
Delays. Each fact sheet defines the disability, describes its characteristics, offers tips for parents and teachers, and connects you with
related information and organizations with special expertise. Also, lists early intervention services by state.
Center for Disease Control and Provention (CDC), Local Health Department & Make-A-Difference Information Network: An
alternative to questions about children development is the local health department or finding testing locations near your community contact the
Make-A-Difference Information Network at 1-800-332-6262
Developmental Delay Resources (DDR):
A nonprofit organization dedicated to meeting the needs of those working with children who have developmental delays in sensory
motor, language, social, and emotional areas. DDR publicizes research into determining identifiable factors that would put a child at
risk and maintains a registry, tracking possible trends. DDR also provides a network for parents and professionals and current
information after the diagnosis to support children with special need.
What is Developmental Delay?
This website answers many of the frequently asked questions about Developmental Delays, the causes of them, what to do if you
suspect DD, early intervention strategies and techniques, special education, and transition.