The US Supreme Court has dismissed a major challenge to "Obamacare", turning aside an effort by Republican-led states to throw out the 11-year-old law that provides healthcare coverage for millions of Americans.
The justices, by a 7-2 vote, left the Affordable Care Act intact in ruling that Texas and other states had no right to bring their lawsuit to federal court.
The administration of President Joe Biden says 31 million people have health insurance because of the law, which is widely known as Obamacare.
"The Affordable Care Act remains the law of the land," Mr Biden said in a statement released by the White House.
"Today’s US Supreme Court decision is a major victory for all Americans benefiting from this groundbreaking and life-changing law.
"It is a victory for more than 130 million Americans with pre-existing conditions and millions more who were in immediate danger of losing their health care in the midst of a once-in-a-century pandemic."
The law’s major provisions include protections for people with pre-existing health conditions, a range of no-cost preventive services and the expansion of the Medicaid programme that insures those with lower incomes or those who have jobs that do not provide health insurance.
Because of the act, most privately insured women receive birth control free of charge as well as routine screenings for cancer and other conditions as they are considered preventive.
Another hugely popular benefit allowed young adults to remain on their parents’ health insurance until they turn 26.
For Medicare recipients, Obamacare also improved preventive care, and more importantly, closed a prescription drug coverage gap of several thousand dollars that was known as the “doughnut hole".
The Supreme Court left in place the law’s now-toothless requirement that people must have health insurance or pay a penalty. Congress rendered that provision irrelevant in 2017 when it reduced the penalty to zero.
The elimination of the penalty had become the hook that Texas and other Republican-led states, as well as the administration of former president Donald Trump, used to attack the law. They argued that without the mandate, a pillar of the law when it was passed in 2010, the rest of the law should fall, too.
And with a more conservative Supreme Court that includes three justices appointed under Mr Trump, Obamacare opponents hoped a majority of the justices would finally kill off the law they have been fighting for more than a decade.
But the third major attack on the law at the Supreme Court ended the way the first two did, with a majority of the court rebuffing efforts to gut the law or get rid of it altogether.
"After more than a decade of attacks on the Affordable Care Act through the Congress and the courts, today’s decision – the third major challenge to the law that the US Supreme Court has rejected – it is time move forward and keep building on this landmark law," Mr Biden said.
The health law is now undergoing an expansion under Mr Biden, who sees it as the foundation for moving the US to coverage for all.
His giant Covid-19 relief bill significantly increased subsidies for private health plans offered through the act's insurance markets while also dangling higher federal payments before the dozen states that have declined the law’s Medicaid expansion.
About one million people have signed up for the programme since Mr Biden reopened enrolment amid high levels of Covid cases this year.