The STAT is an interactive screening measure for autism that assesses behaviors in the areas of play, communication, and imitation skills. In Study 1, signal detection procedures were employed to identify a cutoff score for the STAT using developmentally matched groups of 2-year-old children with autism and with nonspectrum disorders. The resulting cutoff yielded high sensitivity, specificity, and predictive values for the development sample as well as for an independent validation sample. Study 2 examined psychometric properties of the STAT and revealed acceptable levels of interrater agreement, test-retest reliability, and agreement between STAT risk category and ADOS-G classification. The STAT demonstrates strong psychometric properties and shows promising utility as a Level 2 screening measure for autism.