Routine primary health care for all children should involve parents’ descriptions and observations of important developmental landmarks, such as a baby’s capacity to look and listen, relate to a caregiver with joy and pleasure, and engage in reciprocal interactions involving facial expressions, gestures, and vocalizations.  Routine health care should involve formal screening assessments at periodic intervals to identify infants, toddlers, and preschool children at risk for autistic spectrum or other developmental disorders.  Screening tools should be especially sensitive to problems with reciprocal interactions, purposeful social gesturing (e.g., pointing), functional (meaningful) language, and the emergence of pretend play and interactions with peers.  At-risk children should immediately receive a full assessment and, if indicated, an intervention program.  Children have the best chance of making progress when challenges are identified and worked with early.