We know that one of the most effective approaches for autism diagnosis is regular screening for autism during well-child pediatric visits, using a sensitive screening tool (such as the M-CHAT-R).  Led by Drexel University’s Diana Robins, the FAST study is following up with individuals who, as toddlers, screened negative for autism on the M-CHAT-R. In this large, low-risk sample, we will examine the current status of individuals ages 7-14 years who screened negative as toddlers, children who screened positive but were lost to follow-up, and children who screened positive but were not diagnosed with ASD upon detailed evaluation. Our aim is to measure prospective sensitivity for missed cases.