The current paper presents a lifespan model of ethnic-racial identity (ERI) from infancy into adulthood. We conceptualize that ethnic-racial priming during infancy prompts nascent awareness of ethnicity/race that becomes differentiated across childhood and through adulthood. We propose that the components of ERI that have been tested to date fall within five dimensions across the lifespan: ethnic-racial awareness, affiliation, attitudes, behaviors, and knowledge. Further, ERI evolves in a bidirectional process informed by an interplay of influencers (i.e., contextual, individual, and developmental factors, as well as meaning-making and identity-relevant experiences). It is our goal that the lifespan model of ERI will provide important future direction to theory, research, and interventions. Ethnic-racial identity (ERI) encompasses the process and content that defines an individual's sense of self related to ethnic heritage and racial background. It includes labels individuals use to define themselves according to ethnicity/race; awareness, beliefs, attitudes, and knowledge they have about their ethnic-racial background; enactment of their identity; and processes by which each of these dimensions evolve (Umaña-Taylor et al., 2014). ERI is recognized as an important developmental competency (Williams et al., 2012) that can promote positive adjustment in the face of risk or adversity (Neblett et al., 2012). Scholars emphasize that ERI development is dynamic and evolves throughout the lifespan (Syed et al., 2007). However, most conceptual models of ERI have focused independently on distinct developmental periods, such as childhood (e.g., Bernal et al., 1990) or adolescence (see Umaña-Taylor et al., 2014 for review), without an explicit lifespan perspective. This relatively piecemeal approach makes it difficult to chart continuity across developmental periods when identity components are defined specific to a single developmental period, with little effort tracing either the origin or maturation of components beyond a single developmental period. The resulting scholarship gives the impression of disjointed development of ethnic-racial identity. To piece together disparate scholarship in the field's conceptual understanding of ERI, [Adriana Umaña-Taylor and Esther Calzada] assembled a work group funded by the National Science Foundation. The goal of our work group was to develop an integrated model of ERI development that would describe when components of ERI first emerge, how they unfold from one developmental period to another, which components have 2 WILLIAMS ET AL.