The Acute Care for the Elderly (ACE) Tracker is an innovative clinical decision support tool generated from the electronic health record (EHR). 1 The EHR delirium marker is derived from variables noted on the ACE Tracker: nursing documentation in the EHR, use of physical restraints, and pharmacological treatment for delirium (use of quetiapine, haloperidol, olanzapine, or risperidone). The combining of these data elements is consistent with a previous study. 2 The EHR delirium marker was intended to be used by the healthcare team during interdisciplinary team meetings and remote consultation by the “e-Geriatrician.” The purpose of this investigation was to examine the validity of the EHR delirium marker in identifying individuals with delirium.