Attention-deficit/hyperactivity disorder (ADHD) is one of the most common mental disorders of childhood. It is characterized by a pattern of inattention, impulsivity, or hyperactivity that leads to functional impairment experienced in multiple settings. Symptoms of ADHD occur during childhood, and many children continue to have symptoms and impairment through adolescence and into adulthood. This report describes the percentage of children and adolescents ages 5-17 years who had ever been diagnosed with ADHD from the 2020-2022 National Health Interview Survey (NHIS).