The proposed four-stage model proposes that drug use identity, a latent factor, undergoes a progressive transformation from identity as a casual user during the initiation state (Stage 1), to identity as a drug addict at the treatment entry stage (Stage 2), to identity as a recovering addict at the late treatment stage (Stage 3). At the posttreatment recovery stage (Stage 4), this new identity as a recovering addict may operate as a mediator of the social influences effected by a sober reference group. These social influences prompt a sustained identity as a recovering addict, along with enhanced ethnic pride, increased social role responsibility, and enhanced health motivation and behavior. For drug-addicted Mexican Americans, enhanced ethnic pride, whether discovered or reestablished, may develop as a consequence of a progression toward a maturing identity. Directions for theory and research based on this framework are discussed. Figure and 41 references