The U.S. Supreme Court on Friday announced it will take up a legal challenge brought by conservative forces against the Affordable Care Act, the law claimed by the Obama adminstrative to be its signature domestic policy achievement.

The challenge to the sweeping legislation that overhauled many aspects of the for-profit U.S. healthcare system is directed at whether or not federal subsidies designed to make now-mandated private insurance policies more affordable can be offered to people who live in states that decided against establishing their own insurance exchanges and instead opted to depened on exchanges built by the federal government.

As the Washington Post reports: