Language in autism is heterogeneous, with a significant proportion of individuals having structural language difficulties and inclusion of language impairment as a specifier under "Diagnostic and Statistical Manual of Mental Disorders" (5th ed.) criteria for autism. This systematic review asked: What are the reporting patterns of variables pertaining to structural language in autism prior to and after publication of the "Diagnostic and Statistical Manual of Mental Disorders" (5th ed.)? What norm-referenced assessments does research use to characterize the language abilities of autistic individuals with respect to language impairment? This preregistered review (PROSPERO: CRD42021260394) followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Searches took place in September 2022 and included Linguistics and Language Behavior Abstracts, PsycINFO, PubMed, and the Directory of Open Access Journals. Search terms included three essential concepts: autism, language, and age. Two coders independently screened and evaluated articles. Searches yielded 57 qualifying studies, with mostly consistent reporting practices prior to and after the "Diagnostic and Statistical Manual of Mental Disorders" (5th ed.). Studies varied in how they defined language groups and in what norm-referenced measures they used. Interpreting research on structural language in autism requires attention to diagnostic and grouping criteria. Although inconsistency in reporting in original studies limited this review, better understanding the available information on structural language in autistic individuals aged 3-21 years may support identification of language needs.