The US Senate has taken a first concrete step toward dismantling Obamacare, voting to instruct key committees to draft legislation repealing President Barack Obama's signature health insurance program.
The resolution, passed in the early hours of Thursday in a 51-48 vote, now goes to the House of Representatives, which is expected to vote on it this week.
Scrapping Obamacare is a top priority for Republican president-elect Donald Trump and the Republican majorities in both chambers.
Republicans have said the process of repealing Obamacare could take months, and developing a replacement plan could take longer.
But they are under pressure from Mr Trump to act fast after he said on Wednesday that the repeal and replacement should happen "essentially simultaneously."
Twenty million previously uninsured Americans gained health coverage through the Affordable Care Act, as Obamacare is officially called.
Republicans say they want to replace it by giving states, not the federal government, more control over health insurance.
But in recent days some Republicans have expressed concern about the party's current strategy of voting for a repeal without having a consensus replacement plan ready.
House Speaker Paul Ryan said this week he wants to pack as many replacement provisions as possible into the legislation repealing Obamacare
The resolution approved on Thursday instructs committees of the House and Senate to draft repeal legislation by January 27.
Both chambers will then need to approve the resulting legislation before any repeal goes into effect.