House Republicans may have to vote again on the American Health Care Act (AHCA) after narrowly passing the bill earlier this May.

House Speaker Paul Ryan has not sent the AHCA to the Senate yet because the bill may have to be reworked, depending on how the Congressional Budget Office (CBO) scores the bill. House leadership wants to ensure that the bill conforms with the Senate’s rules for budgetary reconciliation, a mechanism that allows the Senate to pass bills with a simple majority.

The House quickly pushed through the AHCA after they added the MacArthur amendment, which allows states to obtain waivers to repeal Obamacare regulations that raise the cost of premiums.

The House rushed the AHCA through without a CBO score that would allow lawmakers and the American people to evaluate the bill’s effects on costs and health insurance coverage. Previous CBO scores of the AHCA estimated that 24 million Americans could lose insurance by 2026, while the previous version would save $150 billion between 2017 and 2026 compared to the original bill, which would have saved $337 billion.

The AHCA waivers that allow states to disregard certain Obamacare regulations could allow citizens to sign up for cheaper insurance. The bill’s $138 billion in funding for high-risk pools could drastically change the cost of premiums and health insurance coverage for millions of Americans.

According to several Congressional aides and procedural experts, if Republicans send the bill to the Senate and the CBO confirms that the bill does not save at least $2 billion, the Republicans would have to restart the repeal process with a new budget resolution. Congressional rules would prevent Republicans from fixing the AHCA after the bill moves to the Senate.

The Senate’s rules require that the AHCA must hit a separate $1 billion in spending cuts in the Finance Committee as well as the health committee. Republican aides added that falling short of those targets would force the House to rewrite portions of the bill, even if the AHCA meets the overall deficit reduction targets.

If the House leadership holds onto the bill until after the CBO unveils their score, then the House can still address the problems explained by the CBO through another vote on the House floor.

Ryan told radio host Hugh Hewitt last week that he does not think that the House will need to vote again on the AHCA. Speaker Ryan said, “We just want to, out of an abundance of caution, wait to send the bill over to the Senate when we get the final score.”

House Republicans could cloak the vote through arcane procedural votes, although the vote will still be weighed down by the CBO’s latest revelations about the bill’s impact on health insurance coverage and cost.

Greg Walden, the chairman of the House Energy and Commerce Committee, urged caution regarding the CBO’s score. “We’ve got to wait for the CBO score. To prove that you meet the reconciliation test.”

Congressman Dennis Ross (R-FL) was not aware that House leadership was holding onto the bill. Ross, a member of the House leadership whip team, said, “I had no idea.” Ross added that the prospect of another vote “does concern me.”

Democrats were critical of House Republicans’ unwillingness to delay the vote on the AHCA until the CBO released their scoring of the health care bill.

Louise Slaughter, the ranking Democrat on the House Rules Committee, chided her Republican colleagues. She said, “Every school child knows that when you pass a bill in the House, you send it to the Senate. You don’t hide it in a drawer somewhere for two weeks, while you wait for information that you should have had before you passed it.”