This article describes what Intermediate and Advanced heritage language learners of Mandarin Chinese, Korean, and Spanish can do when writing in their heritage language, and what prevents these writers from performing at the next proficiency level. One hundred eighty-seven samples were collected using the ACTFL Writing Proficiency Test. Each sample is analyzed employing a review form through which floor and ceiling criteria are identified, and the strengths and weaknesses of writing while attempting next-level functions are made evident. The proficiency profiles resulting from this analysis are used to propose pedagogical practices in support of literacy development.