The No Child Left Behind Act (NCLB) provided that by the end of the 2005-06 school year, all teachers in core content areas, teaching in public schools, must be "highly qualified" in each subject they teach. Under the law, "highly qualified" means that a teacher is fully licensed through a traditional or alternative route and has demonstrated subject-matter competence. The "highly qualified" provision of NCLB has alerted the public to a problematic situation and galvanized the states to corrective action. States are working to comply with the federal law (progressing fastest on the student testing provisions) and moving slowly on the requirements regarding teachers. First, research on what makes a teacher "highly qualified" is remarkably soft in its ability to guide policymakers. Reasons for slow progress may be attributed to two of the four pillars of NCLB--(1) research based decision making; and (2) flexibility. Under the flexibility pillar of NCLB, the states have some options. According to the federal regulations, a state can develop a "high, objective, uniform state standard of evaluation" (HOUSE). A state can exercise the flexibility allowed under the HOUSE provision as long as any data used demonstrate that the teacher has content knowledge. In this article, the author describes Tennessee's approach to "highly qualified" and shows how other states, such as Arizona, are exploring HOUSE alternatives.