This study examines the incentive effects of North Carolina's practice of awarding performance bonuses on test score achievement on the state tests. Bonuses were awarded based solely on whether a school exceeds a threshold on a continuous performance metric. The study uses a sharp regression discontinuity design, an approach with strong internal validity around the cutoff of the treatment assignment score, to examine three questions: (1) Do bonuses induce incentive effects to increase math or reading test score gains?; (2) Do bonuses promote "educational triage" based on the achievement level of the student?; and (3) Do bonuses promote a narrowing of the curriculum at the expense of science? The study is set in North Carolina public schools elementary schools (statewide) in the spring of 2008. The study finds evidence consistent with the hypothesis that educators in North Carolina respond to incentives to increase test score gains in reading and math. Those students in schools that just missed the bonus threshold in 2007 have higher test score gains in 2008. This suggests that educators expend additional effort and may implement new practices in response to the failure to receive a bonus. The author finds suggestive, but not conclusive, evidence that math gains are primarily driven by low and average achieving students. Contrary to expectations, reading gains are disproportionately driven by students with the highest within-school achievement. This suggests that either schools targeted high achieving students with reading interventions, which is unlikely, or that schools used whole-school interventions that had positive effects on high achievers and no effects on low achievers. This finding deserves future research into its generalizability across different time periods and investigation of the mechanisms through which this differential effect was produced. The author finds no evidence of a narrowing of the curriculum at the expense of science. This is in contradiction to theory and prior research on a "narrowing of the curriculum" at the expense of low-stakes and non-tested subjects. The fact that the policy is focused on test score gains, rather than levels, however, raises questions about whether incentive effects on test score levels should be expected. That North Carolina's bonus policy had no effect on test score levels may be viewed as a shortcoming of the policy if absolute, rather than relative, levels of performance are also of interest. (Contains 9 figures and 1 table.)