Little is known about the safety of patients hospitalized in clinical units that do not correspond to their illness. In this systematic review, researchers looked at studies of patients placed in a nonpreferred location within the hospital because space in the clinically appropriate location was not available. The included studies also assessed multiple safety outcomes. They found no consistent effect on mortality or readmissions. Studies demonstrated increased use of rapid response teams when patients were not appropriately located, worse patient ratings of care quality, and a range of concerns about safety processes. The varying quality of the evidence has prompted the study team to begin a prospective observational study of appropriate unit placement and adverse events. A WebM&M commentary discussed an incident involving a patient who was boarded in the emergency department due to lack of room in the intensive care unit.