The Obamacare repeal, the AHCA, is currently being contested among house republicans. It has not yet reached the voting period, so there’s no guarantee what exactly would happen or if it would pass. Especially because both sides, that is the house leadership and the opponents, are insisting that their side wold win if it came to a vote.
The reason for this dispute is unsurprisingly because the conservative members of the caucus, the Freedom caucus, and the moderates of the Tuesday group are opposed to each other. The Freedom caucus has managed to push the bill to the right in certain areas and accordingly the majority (though not all) have agreed to vote for the bill. In turn the Moderates then began to oppose the bill because it went to far to the right, and in many cases because it removed the requirement for insurers to provide healthcare to those with pre-existing conditions.
Moderates tend to come from slightly bluer areas within the States, and accordingly concern themselves with protecting a few provisions while rejecting the majority of Obamacare because Republican. Conservatives are solidly red and therefore are allowed to be let ideology dictate how they vote.
At this stage the bill doesn’t look likely to pass, and if it does the more moderate senate will most likely change it and in turn force the conservatives to vote against it the next time it goes to the house.
Honestly I just don’t understand why they haven’t just sucked it up and begun work on fixing the issues with the ACA. Trump could probably bullshit his way into making that look good if he/the republicans really tried.