The Underlying Characteristics Checklists (UCC) are non-standardized assessment tools intended for use with individuals of all ages who have been diagnosed with ASD or who exhibit behaviors that are often related to ASD and require intervention. The UCC is designed to assist in developing targeted interventions and supports for individuals across the lifespan. The domains assessed include: Social; Restricted Patterns of Behavior, Interests, and Activities; Communication; Sensory Differences; Cognitive Differences; Motor Differences; Emotional Vulnerability; and Medical or Other Biological Factors. The UCC includes the Individual Strengths and Skills Inventory (ISSI), a parallel tool for identifying strengths across the same domains. There are five versions of the UCC for use with individuals cross the lifespan.

Intended for high-functioning individuals, ages 18+.