King v. Burwell is the case currently before the Supreme Court that asks whether the Affordable Care Act (ACA) authorizes health-care insurance subsidies for all otherwise qualified people nationwide or only for people who live in states that run their own health care "exchanges." Exchanges are ACA-defined marketplaces in which people buy health insurance. Under the ACA, states can run their own exchanges or have the federal government run their exchanges for them. About a third of the states have set up their own exchanges; in the others, the federal government runs the exchange for the state.
Under the ACA, subsidies, in the form of tax credits, help pay for premiums. Other costs, such as deductibles, may be subsidized as well. Subsidies are available in differing amounts to people with incomes between 100% and 400% of the federal poverty level. The subsidies are important to the ACA's goals of expanding access to affordable health care and reducing the number of people without health insurance. Because millions of Americans receive insurance through exchanges facilitated for states by the federal government, and about 4.5 million of them received subsidies last year, many people believe that a Supreme Court ruling that subsidies are available only in states with state-run exchanges would severely weaken the ACA.
The U.S. Treasury Department has issued a rule authorizing subsidies in all states, so the U.S. Solicitor General, who is defending the rule in the Supreme Court, has posed the question in the case this way:
Whether the Treasury Department permissibly interprets 28 U.S.C. 36B to make the Affordable Care Act’s federal [tax-credit subsidies] available to eligible taxpayers through the Exchanges in every State.
Read the Solicitor General's brief in King v. Burwell. If you don't have time to read the whole thing, then read only the first 12 pages. It reviews efforts in the states at health care reform that led to the ACA and why, in the government's view, a nationwide system of health-care subsidies was a critical component of what Congress was trying to achieve.
Read all the briefs here.