In a case with potential to scramble the Affordable Care Act, the U.S. Court of Appeals ruled that federal subsidies for health insurance were not properly designed.

If upheld by the Supreme Court, the ruling could limit subsidies on the federal healthcare.gov exchange currently used by 36 states.

Challengers had argued that the law only allows subsides on exchanges run by the states themselves. Supporters of the law argued that was essentially little more than a typo in the law.