The reduction of medication errors is largely dependent upon the structure of the medication management system and the role of the pharmacist in the acute care setting. The significance of this claim became evident in an ethnographic study of nurses’ work in which data were generated from extensive observations, formal interviews, and document reviews. Each step of medication management—from ordering to administering—was microanalyzed, and spaces and places for error emerged. Results revealed medication errors defined by proximity to the patient. Pharmacists became a surprising “stop-gap” between the physicians and patients in the recognition and interception of medication errors occurring far removed from the bedside and did not formally support the reporting of these errors. Understanding the complexity of this process and the roles of involved personnel reminds us that there is presently no fool-proof plan for the reduction of medication errors and implies a culture of safety remains elusive.