This article explores how the research-based practice of using mentor texts can support students' writing within their subject areas. Specifically, this article examines the writing demands of the Common Core Writing Standards and how using mentor texts helps teachers meet these writing standards. We share guiding principles for using mentor texts and explore how to analyze mentor texts in terms of structure and ways with words. Using mentor texts may be a pedagogical practice that content area teachers can find beneficial as they teach writing. Specific examples from social studies and science are provided along with mentor text resources.