We examine heterogenous responses to job-embedded performance incentives along two dimensions theorized to drive motivation: (i) expectations of success when faced with easier versus more difficult tasks, and (ii) ones’ social identity as part of a marginalized group (in our case, race). Compared to the largely lab-based literature on this topic, we leverage data from a fully implemented teacher evaluation system from the District of Columbia Public Schools over a seven-year period (2009-10 through 2015-16). Our regression discontinuity estimates reveal not only that task difficulty and social/racial identity drive much of the incentive effects, but also that there is a strong interaction between the two. Low-performing teachers threatened with dismissal improved much more on tasks with low difficulty and high expectations of success, relative to more difficult tasks (roughly 0.3 SD versus 0.15 SD). These trends were particularly pronounced for Black teachers, who experienced fewer successes than White teachers in the evaluation system generally. We also find that high-performing Black teachers were less responsive than White teachers to an incentive to increase their base pay. At the same time, the responses of Black teachers to the salary incentive were malleable and tracked closely with district-led redesign efforts that aimed to ensure greater equity in terms of teachers most likely to reap the benefits of this incentive.