Story highlights If chosen, this would be a small, but significant change from the House health care bill

Sen. Rob Portman remains against dropping growth rate below the level of the House bill

(CNN) Senate Republicans might move forward with a plan to make even deeper cuts to Medicaid than the House's health care bill, which could be a major blow for Senate moderates.

According to Senate Republican aides familiar with the Senate negotiations, leaders in the chamber are weighing lowering the annual growth rate for the Medicaid program beginning in 2025. Essentially, from that point on, the money states receive for their Medicaid program would be calculated based off standard inflation, CPI-U, rather than medical inflation, which is more generous.

One aide stressed that, at this point, no final decisions had been made, but the option was on the table and would be discussed this week as members attempt to coalesce around a final proposal.

If chosen, it would be a small, but significant change from the House bill that could have a major impact on whether moderate lawmakers ultimately vote for the Senate's version of the Obamacare repeal.

While the idea might help convince conservatives like Sens. Ted Cruz of Texas or Mike Lee of Utah to view a final proposal more favorably, it could be problematic for moderates like Portman or Sen. Dean Heller of Nevada, who faces re-election in 2018.

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