SummaryIdentity theory and social identity theory focus on doing and belonging, respectively, but neither provides a complete picture of being "fully there" at work (Kahn, 1992). This three-wave lagged field study links these two perspectives by proposing that beneficiary-specific prosocial helping identity, met expectations for prosocial helping, and their interaction predict the strength of a contextualized, organization-specific prosocial helping identity (OSPHI) targeted at those same beneficiaries and that OSPHI leads to positive employee work outcomes. Results provide strong support for the model and demonstrate that beneficiary-specific prosocial helping identity had indirect relationships with intent to stay with the organization, experienced work meaning, and emotional exhaustion (negative), via OSPHI, only when met expectations for prosocial helping were weak. We discuss the value of OSPHI as an important construct that reflects the psychological state of "being fully there" at work and predicts subsequent employee work outcomes. Copyright © 2016 John Wiley & Sons, Ltd.Keywords: prosocial identity; organization-specific prosocial helping identity; met expectations; doing and belonging; "being fully there""Identity is peopleˈs source of meaning and experience." Manuel Castells, The Power of Identity, Castells, 2010, p. 6 Identity and identification are "root constructs" in organizational science (Albert, Ashforth, & Dutton, 2000, p. 13) because "every entity needs to have a sense of who or what it is, who or what other entities are, and how the entities are associated" (Ashforth, Harrison, & Corley, 2008, p. 326). Identity theory emphasizes the meanings that people apply to themselves based on the roles they assume (Burke, 1991). These identities reflect what Houser- Marko and Sheldon (2006) called the "self as doer" because roles beget action. Someone with a volunteer identity volunteers (Van Dyne & Farmer, 2005), and someone with a helping identity helps (Farmer & Van Dyne, 2010). Social identity theory and its close relation, self-categorization theory, on the other hand, focus on the meanings people apply to themselves based on group membership (Tajfel & Turner, 1986;Turner, Hogg, Oakes, Reicher, & Wetherell, 1987). These identities reflect social categorization of the self as part of a larger collective (Hogg & Terry, 2000). In contrast to identity theory, which focuses on the self as doing, social identity theory focuses on the self as belonging. This sense of belonging can focus on the group (e.g., Van Knippenberg & van Schie, 2000), the organization (e.g., Mael & Ashforth, 1992), or other collectives.These perspectives on identity and roles (doing) versus social identity and membership (belonging) are important because each has provided conceptual and predictive utility (Hogg, Terry, & White, 1995 Research Article based on role. Nevertheless, given the strongly established traditions of each theory, they are not usually considered together as joint bases of identity. Considered alone neither prov...