Early intervention may contribute to better outcomes in autism, but answering the question "how early?" has significant health and educational implications for age of screening and age of entry into early intervention for children with ASD. The major objective is to directly compare two parent intervention conditions: 1) an individualized parent-implemented intervention (PII) offered in 2-3 weekly sessions to teach parents how to embed strategies to support social communication skills for 25 hours a week within everyday routines, activities, and places; and 2) an information, education and support group (IES) offered twice monthly. Parents of 18-month-old children with autism will be studied. Using outcome measures of social communication and autism symptoms, the effectiveness of PII and IES will be evaluated at 27 months and the effectiveness of the combined interventions will be evaluated at 36 months. This is a supplement to a previously awarded grant with the same title.