Previous research has found that students who are of the same race as their teacher tend to perform better academically. This paper examines the possibility that both dosage and timing matter for these racial complementarities. Using a model of education production that explicitly accounts for past observable inputs, a conditional differences-in-differences estimation procedure is used to nonparametrically identify dynamic treatment effects of various sequences of interventions. Applying the methodology to Tennessee's Project STAR class size experiment, I find that racial complementarities may vary considerably according to the treatment path. Early exposures to same-race teachers yield benefits that persist in the medium run. This same-race matching effect may explain a nontrivial portion of the black–white test score gap.