Current reforms in content area education present new challenges for literacy educators. These reforms promote engaging students in the practices of the disciplines--teaching students how to participate in an activity in which disciplinary content is produced. Content area literacy (CAL) instruction that supports only the learning of general academic or school literacies undermines these content area reforms and their focus on participation because it does not teach the literacies that students need to participate in the disciplines. In this article, the authors present an argument for why CAL instruction should focus on teaching disciplinary literacies instead of a general academic literacy. The authors show how CAL instruction focused on disciplinary literacies can support the educational goals of both literacy educators and content area reformers. The authors also contrast four corresponding characteristics of both types of CAL instruction and illustrate these with examples.