Advance care planning (ACP) has become an increasingly utilized process for exploring and communicating patients' preferences for end-of-life care. This multicenter audit of ACP practices across 12 hospitals in Canada found that even when patients and families have completed ACP, inpatient health care providers are not discussing these preferences during hospitalization nor are they documenting these decisions in the medical record. When there was chart documentation, it did not match the patients' expressed wishes more than two-thirds of the time. The majority of audited cases found that patients were prescribed more aggressive care than they would have preferred. An accompanying editorial argues that these types of "silent misdiagnoses" should be considered medical errors, noting that discussions about code status and ACP are "every bit as important to patient safety as a central line placement or a surgical procedure." A previous AHRQ WebM&M commentary discussed ACP and other tools for expressing end-of-life preferences.