Considerable attention is being paid to hospital readmission as a marker of poor postdischarge care coordination. However, little is known about another potential marker: emergency department (ED) use. We examined ED visits for Medicare patients within thirty days of discharge for six common inpatient surgeries. We found that these visits were widespread and showed extensive variation across facilities. For example, 17.3 percent of these patients experienced at least one ED visit within the postdischarge period, and 4.4 percent of patients had multiple ED visits. Among those patients who were readmitted, 56.5 percent were readmitted from the ED. There was substantial variation-as much as fourfold-in hospital-level ED use for these patients across all six procedures. The variation might signify a failure in upstream coordination of care and therefore might represent a novel hospital quality indicator. In addition, the postdischarge ED visit is an opportunity to ensure that care is properly coordinated and is the last best chance to avoid preventable readmissions.