In recent years, interim assessments have become an increasingly popular tool in districts seeking to improve student learning and achievement. Philadelphia has been at the forefront of this change, implementing a set of Benchmark assessments aligned with its Core Curriculum district-wide in 2004. In this article, we examine the overall context for Benchmarks in Philadelphia, the expectations district leaders had for the use of those Benchmarks, the supports put in place to assist those in schools in meeting those expectations, and the challenges encountered in that implementation.