In Chile, indigenous students obtain lower test scores, on average, than nonindigenous students. Between two cohorts of eighth-graders in the late 1990s, the test score gap declined by 0.1 to 0.2 standard deviations. An Oaxaca decomposition and related descriptive evidence suggest that the most plausible explanation is related to Chile’s large-scale school reforms that were targeted at low-achieving schools and students. The paper evaluates and rules out alternate explanations such as relative improvements in indigenous socioeconomic status, and sorting of indigenous students between schools. The results highlight a potential lever for reducing earnings gaps between indigenous and nonindigenous adults.