Republicans including Trump have campaigned relentlessly on the pledge to dismantle the 2010 reforms.
Washington: The US House of Representatives on Thursday narrowly approved a bill to repeal Obamacare, handing Republican President Donald Trump a victory that could prove short-lived as the healthcare legislation heads into a likely tough battle in the Senate.
The vote to repeal former President Barack Obama's signature domestic achievement, which enabled 20 million more Americans to get health insurance, was Trump's biggest legislative win since he took office in January, putting him on a path to fulfilling one of his key campaign promises as well as a seven-year quest by Republican lawmakers.
It marked a reversal of fortune for the Republican president who suffered a stunning defeat in late March when House Republican leaders pulled legislation to scrap Obamacare after they and the White House could not resolve the clashing interests of Republican moderates and the party's most conservative lawmakers.
Trump has called Obamacare a "disaster" and congressional Republicans have long targeted the 2010 law, formally known as the Affordable Care Act, calling it government overreach.
But despite holding the White House and controlling both houses of Congress, Republicans have found overturning Obamacare politically perilous, partly because of voter fears, loudly expressed at constituents' town-hall meetings, that many people would lose their health insurance as a result.
With Thursday's 217-213 vote, Republicans obtained just enough support to push the legislation through the House, sending it to the Senate for consideration.
No Democratic House members voted for the bill. Democrats say it would make insurance unaffordable for those who need it most and leave millions more uninsured. They accuse Republicans of seeking tax cuts for the rich, partly paid for by cutting health benefits.
The legislation, called the American Health Care Act, is by no means a sure thing in the Senate, where the Republicans hold a slender 52-48 majority in the 100-seat chamber and where only a few Republican defections could sink it.
As Republicans crossed over the vote threshold to pass the bill, Democrats in the House began singing "Na na, na na na na, hey hey hey, goodbye," a rowdy suggestion that Republicans will lose seats in the 2018 congressional elections because of their vote.
Within an hour of the vote, Trump celebrated with House lawmakers in the White House Rose Garden.
"I went through two years of campaigning and I'm telling you, no matter where I went, people were suffering so badly with the ravages of Obamacare," Trump said. "We are going to get this passed through the Senate. I am so confident."
The treatment of people with "pre-existing" conditions was one of the central issues in the House debate on the bill and is sure to resurface in the Senate.
Obamacare prevented insurers from charging those with pre-existing conditions higher rates, a common practice before its implementation. It also required them to cover 10 essential health benefits such as maternity care and prescription drugs.
The Republican bill passed on Thursday would allow states to opt out of those provisions. While insurers could not deny people insurance because of pre-existing conditions, they would be allowed to charge them as much as they want.
In an analysis released on Thursday, healthcare consultancy and research firm Avalere Health said the Republican bill would cover only 5 percent of enrollees with pre-existing conditions in the individual insurance markets.