This article investigates the effect of early-childhood citizenship status on secondary school education of immigrant offspring. Given the potential endogeneity of naturalization decision, I instrument for citizenship by using a German reform that introduced exogenous variation in the age of naturalization. The reform provides powerful instruments, significantly raising the likelihood of possessing a German passport in childhood. I find that citizenship status increases the probability of attending the highest school track, which gives access to academic education. The effects are of a similar magnitude for boys and girls.