An Idaho law prohibits abortions unless necessary to prevent a pregnant woman’s death; the law makes no exception for abortions necessary to prevent grave harm to the woman’s health, like the loss of her fertility. The United States (P) sued D under the Emergency Medical Treatment and Labor Act (EMTALA). That law requires a Medicare-funded hospital to provide essential care to patients experiencing medical emergencies. P contends that EMTALA preempts the Idaho abortion law in a narrow class of cases: when the state law bars a hospital from performing an abortion needed to prevent serious health harm. The District Court entered a preliminary injunction. The en banc Court of Appeals for the Ninth Circuit declined to stay the injunction. D filed an emergency application and the Supreme Court stayed the injunction and granted D’s petition for certiorari before judgment. To ensure appropriate medical care, D’s largest provider of emergency services had to airlift pregnant women out of Idaho roughly every other week, compared to once in all of the prior year (when the injunction was in effect).