The Culture-Language Interpretive Matrix (C-LIM) was developed to help practitioners determine the validity of test scores obtained from students who are culturally and linguistically different from the normative group of a test. The present study used an idiographic approach to investigate the diagnostic utility of the C-LIM for the Wechsler Intelligence Scales for Children-Fourth Edition (WISC-IV) for distinguishing between a referred sample of 69 English language learners, 79 English-speakers diagnosed with Autism, and 216 English speakers referred for a special education evaluation. Results indicated that the WISC-IV C-LIM differentiated between these groups of students at chance rates. Evidence from the previous studies along with the results of the current study does not support the use of the C-LIM for making decisions about individuals in applied practice.