Students' ability to read complex texts is emphasized in the Common Core State Standards (CCSS) for English Language Arts and Literacy. The standards propose a three-part model for measuring text complexity. Although the model presents a robust means for determining text complexity based on a variety of features inherent to a text as well as considerations outside the text, the grammar used in a text is not an overt component of the model. In this essay, we argue that the grammar of a text--especially, the syntactic complexity of sentences in a text--should be included as an explicit and distinct component in a text complexity model due to the fact that grammar contributes to the meaning of text and grammatical meaning impacts reading comprehension. We summarize findings from linguistics research on academic English to support this argument.