This study examined the alignment of three selected U.S. high school textbooks series with the Common Core State Standards for Mathematics (CCSSM) regarding the treatment of statistical association. A framework grounded in the literature for inclusion and exclusion of reasoning about association topics was developed, and textbook entries were compared with the CCSSM learning expectations (LEs). Across the three series, about 77-90% of the 582 association problems addressed two numerical variables. All CCSSM LEs were covered by two of the three series. However, additional association LEs not found in the CCSSM were included in the textbooks. Implications for curriculum revision and development, and content analysis are suggested. The study challenges the notion of CCSSM-aligned curricula.