The justices will hear arguments in the case, called King v. Burwell, next week. It centers on a small piece of the complex health law, with potentially big consequences. At issue is whether the law’s language allows the government to help middle-income people buy insurance everywhere in the country — or only in states that have set up their own insurance marketplaces.
If the court rules for the plaintiffs, the result will be wide schisms in people’s access to health insurance by state. People in Washington, D.C., and the 13 states running their own marketplaces would be unaffected. But residents of the remaining states could lose the subsidies that help them afford insurance, meaning sharp increases in the numbers of uninsured Americans living there. According to one projection, the case could result in eight million more Americans being uninsured in 2016.