This paper uses the case of New York City teachers' interpretations of the labels that are assigned to their performance to explore how teachers experience teacher evaluation systems. Based on our analyses of 141 interviews with New York City teachers, we argue that the ordinal performance labels assigned to teachers by New York City's "Advance" teacher development and evaluation system--Highly Effective, Effective, Developing, and Ineffective--have meanings that extend beyond how they locate teachers in relation to one another, or in relation to an absolute standard of teaching performance. The labels can evoke powerful emotions in teachers, and may stymie policymakers' hopes that they will be motivated by the labels to redouble their efforts to teach well. Teachers' reactions to the labels can also reveal their strategies to resist the redefinition of teachers' work.