The past decade has witnessed escalating legal and ethical challenges to the diagnosis of death by neurologic criteria (DNC). The legal tactic of demanding consent for the apnea test, if successful, can halt the DNC. However, US law is currently unsettled and inconsistent in this matter. Consent has been required in several trial cases in Montana and Kansas but not in Virginia and Nevada. In this paper, we analyze and evaluate the legal and ethical bases for requiring consent before apnea testing and defend such a requirement by appealing to ethical and legal principles of informed consent and battery and the right to refuse medical treatment. We conclude by considering and rebutting two major objections to a consent requirement for apnea testing: (1) a justice-based objection to allocate scarce resources fairly and (2) a social utility objection that halting the diagnosis of brain death will reduce the number of organ donors.