We conducted a content analysis of 27 assessment textbooks to determine how assessment planning was framed in texts for preservice teachers. We identified eight assessment planning themes: alignment, assessment purpose and types, reliability and validity, writing goals and objectives, planning specific assessments, unpacking, overall assessment plan, and other. Themes were used to code the all texts and evaluated the depth of coverage each theme received: mentioning, elaboration, and how to. Findings indicate that classroom assessment textbooks (a) lack a clear focus on assessment planning, (b) demonstrate wide variation in the depth of coverage with little focus on "how to" related to assessment planning, and (c) lack theoretical connections between assessment and instructional practices.