Before brain death criteria, there was only non-heart-beating donation (NHBD). NHBD is associated with longer ischemic times, which caused the practice to fall out of favor after brain death criteria were accepted in the 1970s. Ischemia causes damage by limiting or blocking blood flow to an organ. Within NHBD, there are two types: controlled and uncontrolled. In controlled NHBD, time of death is dependent on withdrawal of life support as determined by the family and physician. Controlled NHBD was expected to yield the greatest number of ‘extrarenal organs’ (i.e. not kidneys). In contrast, uncontrolled NHBD is often from patients suffering a sudden death, such as heart attack. Uncontrolled donations are more complicated because the family must have time to hear about donation and come to a conclusion while organs are still viable. Since this process takes time, uncontrolled NHB donors were expected to contribute mostly kidneys, which can withstand more ischemia. These criteria will expand the number of organs available for transplant and should be implemented in conjunction with other expansion efforts.