Background: Research suggests a number of benefits from teacher participation in school improvement—chief among them that it can increase teacher receptivity to innovation and reform adoption. Improvement science has been put forward as a new paradigm for involving local school stakeholders in the improvement process.

Purpose: We describe the beliefs held by teachers and teacher leaders during the development and implementation of a locally developed innovation. To explain why the beliefs of these two school stakeholder groups would differ, and the implications these differences have on receptivity to the innovation, we merge the sensemaking framework and status risk theory.

Setting: Three high schools in a large urban school district in the southwestern United States.

Research Design: The data for this study come from a seven-year study of the process of scaling up effective practices in a large urban district. This qualitative case study is based on transcripts from 260 semistructured interviews and 24 focus groups with development team members and teachers. We analyzed transcripts to understand participants’ attitudes toward and understanding of the innovation design.

Findings: Allowing for teacher self-determination in the innovation design and implementation helped to garner a high level of teacher buy-in to the innovation. Compared with externally developed reforms, the innovation was less challenging to teacher autonomy and was customized to fit the needs of their students. These conditions led to high levels of teacher ownership over the innovation. Yet, in the process, teacher leaders grounded the innovation in preexisting and easy-to-implement practices that did not require significant investment from teachers to adopt. Conclusions: Teacher self-determination in the innovation development process contributed to greater teacher ownership of, and receptivity to, organizational change, but at the cost of adopting more ambitious practices that likely had a greater chance of improving instruction and positive student outcomes.