Global Developmental Delay (GDD) is a diagnosis used for children under age 5 who show significant delays in two or more developmental domains — gross or fine motor skills, speech and language, cognition, social and personal skills, and activities of daily living. GDD is typically identified when a child scores two or more standard deviations below the mean on standardized developmental assessments. It is considered a provisional diagnosis because young children cannot reliably complete the IQ testing required for a formal intellectual disability diagnosis. As the child grows, the diagnosis may evolve into intellectual disability, autism, a specific learning disability, or the child may catch up to peers. Early intervention services through IDEA Part C are critical for children with GDD.
GDD qualifies children for early intervention under Part C and may establish eligibility for HCBS waivers in states that cover developmental delays beyond autism alone. Early documentation creates a foundation for future service applications.