Barack Obama's signature healthcare law - widely known as 'Obamacare' - has survived a second major legal challenge at the Supreme Court.
The fate of Mr Obama's most important domestic policy achievement was in the hands of America's nine Supreme Court justices after conservatives sued and claimed the healthcare law was illegal. But six of the nine justices sided with the White House and ruled that the Affordable Care Act, as the legislation is formally known, was within the law.
The ruling is a major victory for Mr Obama and ensures that around six million Americans can continue to receive government subsidies towards their health insurance.
Mr Obama appeared in the White House Rose Garden to declare victory an hour after the judgement was handed down.
"The Affordable Care Act is here to stay," he said. "Today is a victory for hard-working Americans all across this country whose lives will continue to become more secure in a changing economy because of this law."
Yesterday's decision is the second time that Mr Obama's healthcare law has survived a near-death experience at America's highest court.
In 2011, conservatives sued the US government and claimed that parts of Obamacare violated the American constitution. The court ruled 5-4 in favour of the White House.
Both times Mr Obama's law has been protected by Chief Justice John Roberts, a conservative judge who was appointed to lead the Supreme Court by George W Bush.
Mr Obama was a senator at the time Justice Roberts was nominated to his post and voted against confirming him to the high court. Yet in both decisions Justice Roberts has gone against his conservative backers and sided with the court's liberal justices to uphold Mr Obama's healthcare law.
Yesterday's case, formally known as King versus Burwell, centred on White House policy that provides subsidies to less wealthy people who cannot afford their own health insurance.
Conservatives argued that the subsidies could be provided only in states that have agreed to set up their own marketplaces for buying health insurance but not in states where local government refused to set up a marketplace and left the responsibility to the federal government.
In practice, this meant that the subsidies for people in Republican-controlled states like Louisiana were at risk while subsidies in Democrat-controlled states like Massachusetts would have been largely unaffected.
Ultimately, the court decided that the issue was moot and that the subsidies should be available across the entire US.