The Pediatric Evaluation of Disability Inventory-Computer Adaptive Test is an alternative method for describing the adaptive function of children and youth with disabilities using a computer-administered assessment. This study evaluated the performance of the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test with a national sample of children and youth with autism spectrum disorders aged 3-21?years. Parents (n?=?365) completed an online survey that included demographics, the Social Communication Questionnaire, and the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test Social/Cognitive, Daily Activities, and Responsibility domains. Item response theory analysis confirmed items in each domain fit a unidimensional model and few items misfit. A large number of items in the Social/Cognitive domain showed differential item functioning, indicating a unique order of item difficulty in this population in this domain. Differences in item difficulty estimates were addressed through a parameter linking (equating) process. Simulations supported the accuracy and precision of the Computer Adaptive Test. Results suggest that the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test, as modified for autism spectrum disorder, is an efficient and sound assessment for this population.