Which IQ range is typically associated with severe intellectual disability?

• A. 35 to 49
• B. around 20 to 34
• C. below 20
• D. 50 to 69

Answer: (B)

Severe intellectual disability is marked by significant limitations in intellectual functioning that require substantial supports for daily living. The range that best fits this level is about 20 to 34 on an IQ test. This sits below the ranges associated with mild and moderate intellectual disability (roughly 50–69 and 35–49) and above the range for profound disability (below 20). So, the 20–34 range is the one that corresponds to severe impairment. Keep in mind IQ is just one piece; adaptive functioning and the level of ongoing support needed are also central to understanding the profile of someone with severe intellectual disability.