This paper extends the theorization of identity grafting (Lee 2017), developed to understand individual cultural identity processes that buttress repression, born-again, integrated, and situational strategies to reconcile identity tensions that arise from change in a Chinese context. A qualitative case study approach is employed to examine two groups of teachers at an elementary school engaged in professional learning communities (PLC) to implement mixed-ability learning. Childhood home language (CHL) is used to identify homogeneous or diverse group cultural identities to typologize the identity grafting strategies of the two PLCs in the case school. The findings show that homogenous and diverse group cultural identity PLCs serve different purposes, and mixed-ability learning is more likely to emerge from PLCs of diverse group cultural identities engaging integrated/situational identity grafting. This paper is the first to extend the theory of identity grafting to study group cultural identities, and the findings demonstrated the potential for transforming identity grafting strategies as teachers engaged these collaborative spaces. The findings also broadened the scope to the study of language as a cultural construct, unveiling how CHL functions as a form of tacit cultural identity, as opposed to overt identities such as nationality and ethnicity.