Writing analytically about text is a valued skill reflected in current academic standards. The quality of text-based writing opportunities in U.S. elementary schools, however, is generally weak, with variation in the rigor of the writing tasks teachers assign. Previous research suggests that teachers' beliefs about instruction significantly contribute to their decision-making; therefore, teachers' conception of text-based writing likely influences the tasks they assign. Yet, teachers' conceptions of text-based writing have yet to be charted. In the present study, through qualitative analysis of interviews, we identified three such conceptions among 4th and 5th grade teachers (n =17)--text-based writing as application of reading skills and strategies (n =10); as inquiry into text ideas (n =5); and a mixed conception, as both skills-and-strategies-based and affective response tangential to text (n =2). Analysis of assigned text-based writing tasks (n = 102) showed that regardless of their conception, all teachers assigned tasks reflecting the assessment and accountability demands of their policy context. Beyond this, teachers' assigned tasks were consistent with their conception. Teachers who held the first conception assigned predominantly tasks focused on demonstrating reading skills. The second group of teachers assigned a greater proportion of tasks guiding students to interpret or analyze big ideas than did other teachers. Finally, teachers holding mixed conceptions assigned routine skills-based tasks and personal or creative writing in near-equal proportions. We argue that teachers' conceptions of text-based writing provide an important leverage point for supporting text-based writing instruction.