Greenwald: Eye movement desensitization and reprocessing (EMDR) has already been defined by at least one EMDR-focused professional association as inextricably based on Shapiro’s (2001) eight-phase protocol and adaptive information processing (AIP) model. This commentary argues that given the lack of data supporting an exclusive preference for Shapiro’s constructs, EMDR’s definition should not preclude legitimate alternative conceptualizations. Since definitions may be used for many inclusive and exclusive purposes with impact on EMDR’s development, dissemination, practice, and reputation, EMDR’s definition should be reconsidered. Shapiro: Greenwald’s arguments and suggested redefinition are examined in relation to EMDR research, theory and practice. As evaluated in numerous studies, EMDR is a distinct, eight-phase integrative psychotherapy approach that consists of numerous procedures and protocols, which were formulated and are conducted in accordance with the principles of the AIP model. Research and published clinical case reports have validated both its utility and predictions of positive treatment outcomes with a variety of populations. Professional implications are explored.