In order to help all students meet the writing expectations of the Common Core State Standards (National Governors Association Center for Best Practices, 2010), researchers need a deeper understanding of the characteristics of struggling writers. The purpose of this study was to explore the profiles of students who may have or be at risk for writing disabilities. First-grade students (N = 391) were assessed using three writing assessments (spelling, sentence writing fluency, writing achievement) at the end of the school year. Using latent profile analysis, students were identified as fitting into one of five profiles (At Risk, Low Fluency, Low Writing, Average, and Above Average). Students also wrote narrative and descriptive texts that were scored multiple ways. Using confirmatory factor analysis, four common factors were identified: Quality/Length, Spelling, Mechanics and Syntax. Students in the At Risk profile wrote narratives and descriptions that scored lower on all aspects of writing when compared to students in the Average and Above Average profiles. These findings provide further evidence of the distinct difference among writers as early as first grade, and they offer insight into the characteristics of at-risk writers. The implications of these findings for instruction and assessment and directions for future research are described. [This paper was published in "Journal of Learning Disabilities" 2018 (EJ1180586).]