1. How many people have IDD?
- 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