1. How many people have IDD?

People with IDD in the United States. Infographic of 100 silhouettes of people arranged in 5 rows of 20. These people represent 7.39 million people with intellectual and developmental disabilities in the US in 2019. A blue box is drawn around 22 people, representing 22% of people with IDD known to state IDD agencies. 19 of those 22 are highlighted in green, representing 19% of people with IDD who received long-term supports and services through state IDD agencies.
  • An estimated 6.99% of children and 0.78% of adults in the United States have intellectual or developmental disabilities. Based on those estimates, there were 7.3 million people with IDD in the United States in 2019.
  • These estimates change as prevalence estimates are updated.
  • Of the people with IDD in the US, an estimated 22% or 1.58 million people are known to state IDD agencies.
  • Nearly all people known to state IDD agencies get case management. An estimated 1.40 million (19%) receive additional long-term supports or services