We are fortunate to have invited commentaries from the laboratories of Dr Cathy Lord and Dr Fred Volkmar offering their perspectives on the new Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 criteria for the autism spectrum. Both commentaries note how DSM-5 collapses the earlier diagnostic categories of the pervasive developmental disorders into a single category of autism spectrum disorder. In addition, DSM-5 collapses social and communication domains into a single combined domain. The commentaries go on to discuss the positive aspects of these changes and raise some areas of potential concern. We support the evidence-based changes to autism diagnosis found in DSM-5, and look forward to further studies on the autism phenotype as this has implications for diagnosis and treatment. As our mechanistic understanding of autism improves, diagnoses based on behavioral parameters will continue to provide opportunities for interventions targeting the behaviors, while etiological diagnoses will provide opportunities for interventions tailored to etiology.