Teachers' knowledge of reading comprehension processes is under-researched relative to teachers' knowledge of word identification and phonological awareness. In this study, sixty-two pre- and inservice upper-elementary and middle school English language arts, science, and social studies teachers completed in-depth interview protocols eliciting multiple aspects of knowledge about reading comprehension processes. Using qualitative analyses, we found that teachers in the sample demonstrated knowledge in four consistent areas: strategizing, grappling to achieve coherence, leveraging and producing knowledge, and participating socially. We propose these concepts as a starting point for characterizing teachers' knowledge of how comprehension processes work when they are well developed. We discuss implications of these findings for future research and practice in literacy teacher education.