Set in a collective bargaining state in the Northeastern U.S., this exploratory case study investigated how a sample of 12 public school principals interpreted new teacher evaluation processes required by Race to the Top (RTTT). Principals reported that the RTTT evaluation system disrupted established routines and contractual guidelines for evaluating all their teachers and held principals more accountable for supervision and evaluation processes. The embedded evaluation protocols and rubrics established clearer expectations for teachers' performance, and aligned state-, district-, and school-level instructional goals. However, principals believed the RTTT policy emphasis on teachers' ratings raised concerns about their teachers' employment status, professional growth, and instructional improvement. Our findings suggest that principals may have difficulty balancing instructional supervision and evaluation processes in these types of high-stakes policy systems.