This study examined classrooms in three, high performing, public secondary schools serving high need communities. Of 22 classes observed, we found approximately one third exhibited an instructional demand for 21st century skills. In many of the remaining classes, teachers appeared to apply misconceptions of 21st century skills, and unintentionally deployed those misconceptions to reinforce the narrow and shallow skill set associated with test-based accountability. Themes from teacher and administrator interviews support this finding. School and system level implications are discussed.