The Barkley Deficits in Executive Functioning Scale (BDEFS), authored by Russell A. Barkley and published by Guilford in 2011, is an individually administered assessment tool that may be used to evaluate adults ages 18 to 81. The purpose of this measure is to screen those who may be experiencing executive functioning (EF) deficits in self-organization, self-restraint, selfmotivation, self-regulation of emotion, and self-management to time. Although it is not meant to be a diagnostic instrument, the BDEFS can be administered in a clinical, research, or industrial-organizational setting as a time and cost-efficient means of identifying those with potential difficulties. The BDEFS is both theoretically and empirically based, and its conceptualization was well grounded in the literature on executive functioning. The BDEFS is the only instrument to evaluate the type and extent of EF deficits present in daily activities over an extended period of time, as other measures of EF merely provide a momentary assessment of EF deficits. The availability of multiple versions and various lengths allows for effective and efficient administration across settings and using multiple perspectives.