The Change Laboratory methodology offers the potential to support expansive learning in preservice bilingual teacher education. This qualitative case study examines how ten preservice Chinese and Korean bilingual teachers, who participated in a Change Laboratory intervention, engaged one of the major Change Laboratory instruments, the four-field model, to make changes in their lesson implementation. By recognising the structural barriers in their bilingual teacher learning and praxis, they were able to take future-oriented actions. Findings from the thematic analysis illustrate how, as the preservice bilingual teachers embraced ambiguity in their teaching, they became increasingly cognisant of the non-linear and complex nature of teaching and learning. In doing so, they explored their collective reflective practices and gained confidence in using their judgement to generate expressions of transformative agency that have the potential to disrupt the status quo in US bilingual education.