With an anticipated shortage of ventilators for patients with coronavirus disease 2019 (COVID-19), hospitals, physicians, and nurses may have to make an unprecedented decision: should they withdraw or withhold ventilators from some patients and use them for other patients who have a better chance of survival? It is not uncommon for care teams to decide against initiating or continuing mechanical ventilation when such treatment would not achieve a patient's goals or directives. COVID-19 presents a different case: patients who do not receive a ventilator could benefit, perhaps living for many additional years, if they receive short-term mechanical ventilation. Denying patients such treatment, against their wishes, most likely will result in their death, but it will also make this scarce resource available to other patients who are more likely to survive if they receive ventilator support.Recently developed protocols expressly call for the rationing and reallocation of ventilators, in a manner that aims to save the greatest number of lives. 1 These protocols are broadly accepted by medical ethicists. 1,2 But ethics aside, there are potential legal ramifications of either withholding or withdrawing a ventilator from a patient who would ordinarily receive such aid in the absence of a public health emergency.In this Viewpoint, we assess the legal risks that physicians, other health care workers, and hospital systems confront in such scenarios and recommend that states explicitly and immediately adopt legal protections for health care workers, modeled on provisions in place in Maryland.