Over the past 20+ years, researchers have worked toward identifying early behavioral predictors of autism spectrum disorder (ASD) and developing observation-based screeners to supplement existing parent-report methods. This study is a follow-up, 3 to 8 years later, with parents/caregivers of 57 children previously enrolled in a U.S. university-based study evaluating early ASD-risk. The original study evaluated infants' (ages 15-35 months) ASD-risk through both observation-based and parent-report screeners. At follow-up, caregivers completed a phone interview inquiring about their child's developmental progress and diagnostic outcomes. Results indicated screener at-risk status agreement in infancy predicted only one of the four parent-reported ASD diagnoses at follow-up. Single instrument at-risk status aligned with two additional ASD diagnoses (one per screener), and both screeners missed one ASD diagnosis at follow-up. Results did not indicate significant added utility for the observation-based screener over the commonly used parent-report screener, suggesting that ASD behavioral markers may be hard to observe at early ages.