The increasing intra-national diversity of many modern markets poses challenges to identity segmentation. As consumers require greater recognition of their diverse identities from brands, marketing science and practice are in search of theories and models that recognize and capture identity dynamics as impacted by cultural influences both from beyond and within national market borders. This paper extends consumer acculturation theory into multicultural market realities and offers a Consumer Multicultural Identity Affiliation (CMIA) Framework2 that distinguishes and integrates three key types of intra- and trans-national cultural influences informing identity dynamics. By examining consumer cultural identities within the CMIA framework in a mixed-method, two-country study, we show that gaining such an integrative view on cultural identity affiliations uncovers greater diversity and complexity (mono-, bi-, or multi-cultural) of consumer segments. We conclude with discussing future directions for CMIA applications to support marketing managers, scholars and educators dealing with culturally heterogeneous markets.