The No Child Left Behind Act's requirements for a highly qualified secondary school teacher include a "demonstrated high level of competency in each of the academic subjects in which the teacher teaches." This requirement involves a clear-cut division: secondary school teachers must be qualified in their subject while an elementary credential is sufficient for elementary school. But what about middle school teachers? Until now, middle grades instructors have been able to avoid mastery of subject content knowledge by receiving their credential in elementary education. NCLB groups them instead with secondary teachers and demands that they have certification in a subject area. Pennsylvania has responded to the demands of the new federal law by creating new teaching certificates for the middle grades, such as "middle level English." In June, August, and September, about 4,000 teachers took exams in middle-level math, science, social studies, or English. But the state estimates that 15,000 teachers could be affected by NCLB's stronger subject content requirement. The state is paying for teachers to take the new test but only on three dates. After that, teachers will have to pony up the $80 exam fee themselves.