Children who are later diagnosed with autism and/or attention deficit hyperactivity disorder (ADHD) have distinctive health care utilization patterns in their first year of life that differ from patterns of non-affected children. The early utilization patterns could be used for early identification of autism or ADHD. Post-diagnosis, children with autism or ADHD have health care utilization and costs that are double or triple the level of children without either of the two diagnoses. Between birth and 12 months, children later diagnosed with autism had higher odds for the following: 5 times higher likelihood of having . . .