What time is the health care vote today? Here's when to expect a tally on the GOP plan.

The House of Representatives was expected to vote on Republicans' health care bill, the American Health Care Act, on Thursday, but with support for the bill lacking, the vote was postponed until Friday in an attempt to get additional Republicans on board.

House GOP leadership indicated they would vote on the bill Thursday whether or not it had enough support to pass, but later decided to postpone the vote until Friday. The exact timing of the vote is still unknown, though journalist Frank Thorp noted on Twitter it would likely take place roughly between 3:45 and 4:45 P.M.

As of Thursday morning, 29 House Republicans had come out against the bill (and three more had said they likely wouldn't vote for it). The GOP can afford to lose only 21 members, assuming no Democrats vote for the bill.

According to multiple media reports, Trump spent Wednesday evening and Thursday morning cajoling House Republicans and offering concessions in exchange for their support. 

In the face of Thursday's postponement, Trump signaled he was ready to move on from the health care debate by issuing an ultimatum: Vote for the bill, or be "stuck with Obamacare."

Republicans attempted to persuade members of the far-right House Freedom Caucus to vote for the bill by proposing additional changes Wednesday night, which scrapped the Affordable Care Act's requirement that health care providers cover basic "essential health benefits," including maternity care, hospitalization and outpatient services. 

On Thursday night, lawmakers partially softened the blow of the massive change by adding an additional amendment, which would allow states to establish their own guidelines for what constitutes an "essential health benefit."

Whether these changes — and Trump's ultimatum — will win over the Freedom Caucus remains to be seen until Friday's vote.

“The choice is yes or no,” Rep. Joe Barton, a member of the Freedom Caucus, said on Thursday night, the New York Times reported. “I’m not going to vote no to keep Obamacare. That’d be a stupid damn vote.”

March 24, 2016, 11:15 a.m. Eastern: This story has been updated.