Every year, people make decisions based on trust in the certainty of diagnoses of brain death. These decisions range from signing an organ donation card to withdrawing life support from a loved one. Two recent developments have revived concerns about medical standards for determining brain death. One is a recent study on variability in brain death policies in the United States; the other is the filing of a federal lawsuit to rescind the death certificate of Jahi McMath, a teenager who (...) appears to have survived a 2013 declaration of brain death. The author examines these developments and asks whether trust in the certainty of brain-death determinations is currently warranted. (shrink)