Sen. Marco Rubio and Rep. Paul Ryan are collaborating on an Obamacare alternative and could announce the proposal as early as this month, according to Republican sources.

Both Republicans have been regularly engaged in pushing legislation on major issues — and both have made it a habit to form cross-chamber partnerships to further those endeavors.

But this particular partnership is notable given the high-profile nature of health care reform and that Rubio, Florida's junior senator, and Ryan, the House Budget Committee chairman from Wisconsin, are both considered possible contenders for the Republican presidential nomination in 2016.

Aides to Rubio and Ryan declined to discuss the forthcoming proposal when asked about it Wednesday afternoon.

"Congressman Ryan continues working with his colleagues, including reformers like Sen. Rubio, on better solutions to deliver quality, affordable coverage to American families," Ryan spokesman William Allison said.

“I don’t have anything to announce today,” Rubio told the Washington Examiner.

However, such a proposal could influence GOP health care policy as congressional Republicans search for an alternative to the Affordable Care Act to coalesce around ahead of the 2014 midterms. The proposal also could affect how Republicans approach repealing and replacing Obamacare next year if the GOP wins the Senate in November.

Ryan, the 2012 GOP vice-presidential nominee who is set to take over as House Ways and Means Committee chairman in January, has left the door open to a presidential run in 2016. Rubio said in a recent interview with conservative radio talk show host Hugh Hewitt that he could decide by this time next year whether to run for president or seek re-election to his Senate seat.