The U.S. Supreme Court has decided to hear another controversial challenge to the Affordable Care Act, better known as Obamacare. The court announced Friday that it will take up King v. Burwell, in which plaintiffs argue that language in President Barack Obama's signature domestic policy achievement is worded in an ambiguous manner, and that Congress didn't intend for the federal government to issue health insurance subsidies to Americans.

The law is the latest in a long series of attempts by opponents of the law to undermine it, both via the court system and by congressional action. This case is different in that it doesn't question the law's constitutionality, as in the other high-profile challenge to reach the Supreme Court, which centered around the legality of Obamacare's individual mandate. The court ruled 5-4 that the Affordable Care Act was constitutional in June 2012. It also determined that its requirement that people purchase health insurance was permissible under the Commerce Clause.

The Supreme Court, by taking on King v. Burwell, will look instead to resolve a disagreement in the lower courts, which have offered differing opinions on whether Congress intended, when it drafted the law, for both state and federal subsidies to be doled out to people who buy insurance through exchanges. Some critics of Obamacare believe that the law is unclear on the topic.

The U.S. Court of Appeals for the D.C. Circuit and the 4th Circuit Court handed down conflicting rulings on the case in July, setting up the possibility for the showdown that the Supreme Court has agreed to take on.

Exactly what way the Supreme Court is leaning on the case will remain difficult to estimate until arguments are heard. But it will be the subject of much attention, as it threatens a key tenet of Obama's health care law.

"This lawsuit reflects just another partisan attempt to undermine the Affordable Care Act and to strip millions of American families of tax credits that Congress intended for them to have," the White House said in a statement. "We will continue to ensure that every American has the peace of mind of having access to affordable insurance."