We bring together education research on factors shaping teacher learning with institutional research on policy shifts and conflicts to explore an instructional policy shift in one school district. Specifically, we compare mathematics teacher learning opportunities in three elementary schools over a three-year period during which a district policy shift toward English as a Second Language (ESL) instruction diverted attention from mathematics curriculum reform efforts. Findings demonstrate that while the policy shift led to significant decreases in mathematics teacher learning opportunities across the district and in two of the case study schools, mathematics teacher learning opportunities were sustained in one case study school due to two school-level strategies: a common, articulated vision for mathematics instruction and a high number of mathematics-focused teachers in the school. Together, these two strategies supported the creation of coherence between mathematics and ESL policies in the school, which encouraged the maintenance of mathematics teacher learning opportunities. (Contains 7 notes and 5 tables.)