The measurement and development of ethnic identity of Koreans living in the United States and China were examined in the context of different migration experiences. Three hundred sixteen undergraduate college students were administered the Multigroup Ethnic Identity Measure (MEIM; J. S. Phinney, 1992). Separate principal-component analysis for each sample was performed to create cross-culturally equivalent Ethnic Identity and Other-Group subscales. Differential item function analysis revealed no cultural item bias among the retained MEIM items. Korean Americans had higher scores on the Ethnic Identity and Other-Group subscales and were more likely to be classified as bicultural than were Korean Chinese. Korean Chinese were more likely to be classified as assimilated, traditional, or marginalized in their cultural orientation.