Virtually all states require teachers to undergo licensure testing before participation in the public school labor market. This article analyzes the information these tests provide about teacher effectiveness. The authors find that licensure tests have different predicative validity for student achievement by teacher race. They also find that student achievement is impacted by the race/ethnicity match between teachers and their students, with Black students significantly benefitting from being matched with a Black teacher. As a consequence of these matching effects, the uniform application of licensure standards is likely to have differential impacts on the achievement of White and minority students. (Contains 9 tables, 1 figure and 23 notes.)