In this article, the authors examine the conceptualization and measurement of ethnic identity as a multidimensional, dynamic construct that develops over time through a process of exploration and commitment. The authors discuss the components of ethnic identity that have been studied and the theoretical background for a developmental model of ethnic identity. The authors review research on the measurement of ethnic identity using the Multigroup Ethnic Identity Measure (J. Phinney, 1992) and present a revised version of the measure. The authors conclude with a consideration of the measurement issues raised by J. E. Helms (2007) and K. Cokley (2007) and suggestions for future research on ethnic identity.