While attention dysregulation is a promising early indicator of neurodevelopmental risk, in particular attention-deficit/hyperactivity disorder (ADHD), it is difficult to characterize clinical concern due to its developmental expectability at the transition to toddlerhood. Thus, explicating the typical:atypical continuum of risk indicators is among the key future directions for research to promote early identification and intervention, and prevent decrements in the attainment of developmental milestones into early childhood. In this paper, we present the Multidimensional Assessment Profiles-Attention Regulation Infant-Toddler (MAPS-AR-IT) Scale, a novel parent-report survey of dimensional, developmentally specified indicators of attention (dys)regulation. Item Response Theory was employed to characterize the typical:atypical spectrum of both normative and more concerning dysregulation (including the contexts in which behavior occurs). We provide evidence of the validity of this measure in capturing the full typical:atypical spectrum via a longitudinal sample of typically developing children at 12-18 months of age (baseline) via concurrent scores on well-validated temperament and clinical measures. We also examine longitudinal stability and predictive validity if the MAPS-AR-IT via a clinical interview of ADHD symptoms at 24-30 months (follow-up). While not diagnostic, we present evidence of the utility of the MAPS-AR-IT in explicating individual neurodevelopmental risk and elucidating the broader typicality of behaviors related to attention (dys)regulation.