We investigate the predictive validity of teacher credential test scores for student performance in secondary STEM classrooms in Washington state. After replicating earlier findings that teacher basic skills licensure test scores are a modest and statistically significant predictor of student math test score gains in elementary grades, we focus on three subject/grade combinations--middle school math, ninth grade algebra and geometry, and ninth-grade biology--in which both current and prior year subject area test scores are available and estimate value-added models that provide within-subject estimates of the relationship between teacher licensure test scores and student achievement gains. We find that basic skills tests are modestly predictive of student achievement in middle and high school math and highly predictive of student achievement in high school biology. On the other hand, subject-specific tests are a statistically significant predictor of student achievement only in high school biology.