Senate Republicans’ planned changes to Medicaid to save the federal government hundreds of billions of dollars are in question Thursday after the Senate rules referee found several major provisions violate the chamber’s rules.

The rulings from the Senate parliamentarian could deal a significant blow to President Trump’s “big, beautiful bill,” although the Medicaid reforms are a bigger priority for fiscal hawks in Congress than the president himself.

The Senate parliamentarian, Elizabeth MacDonough, ruled that six Medicaid provisions, including a crackdown on state provider taxes that some Republicans oppose, violate the Senate’s Byrd Rule guiding what can be included in budget reconciliation.

She also ruled against a few provisions that would have prevented most categories of noncitizens from qualifying for Medicare benefits and premium tax credits that help subsidize health insurance purchased through the Affordable Care Act Marketplaces.

Budget reconciliation is the process Republicans are using to advance the Trump agenda bill without the threat of a Democratic filibuster. Any provisions found to violate the Byrd rule lose that filibuster-proof status and would require 60 votes to remain in the bill.

The Byrd Rule, named after the late Sen. Robert Byrd of West Virginia, says policy changes made in reconciliation must have more than a “merely incidental” impact on the federal budget — meaning the primary goal must be to shift federal spending or revenues, not make policy.

The Senate parliamentarian doesn’t publicly share her decisions. The Senate Budget Committee Democrats have announced which provisions she has ruled out of compliance but have not shared her full rationale.

Some House Republicans have already called for their Senate counterparts to overrule the parliamentarian. While that technically can be done with a simple majority vote, many Senate Republicans, including Majority Leader John Thune, view that as a nuclear option akin to gutting the filibuster and don’t want to open that Pandora’s box.

Sen. Tommy Tuberville, Alabama Republican, posted on social media that the parliamentarian is an unelected bureaucrat who should be fired “ASAP.”

“The WOKE Senate Parliamentarian, who was appointed by Harry Reid and advised Al Gore, just STRUCK DOWN a provision BANNING illegals from stealing Medicaid from American citizens,” he said. “This is a perfect example of why Americans hate THE SWAMP.”

Ms. MacDonough’s rulings against the Medicaid provisions come as Senate Republicans were already struggling to find enough support among their ranks for their provider tax crackdown.

The Senate measure sought to force most states to lower provider tax rates to no more than 3.5% by 2031 if they want to use the revenue to pay for increased Medicaid payments to the same providers, which would inflate the cost of their Medicaid programs and the share the federal government must contribute.

The change in what is known as the “safe-harbor” limit, currently 6%, would only apply to the 40 states and the District of Columbia that expanded Medicaid under Obamacare to include low-income, able-bodied adults without dependents earning up to 138% of the poverty level. Those states receive a 90% federal contribution to cover the additional beneficiaries and thus are more incentivized to use higher provider taxes to inflate the amount of funding they receive from the federal government.

Democrats who had challenged the provision and others as part of the Byrd Rule review celebrated Ms. MacDonough’s decision.

“The parliamentarian has made clear that reconciliation can not be used to manipulate state provider tax policies, which would have resulted in massive Medicaid cuts that hurt kids, seniors, Americans with disabilities and working families,” said Oregon Sen. Ron Wyden, the top Democrat on the Senate Finance Committee, which has jurisdiction over Medicaid.

Ms. McDonough also ruled several other Medicaid provisions violate the Byrd Rule, including one to prohibit Medicaid spending on sex-change treatments for transgender people.

Other Medicaid provisions she ruled against sought to limit access to the program for noncitizens and reduce federal funding to states that continue to provide coverage to certain categories of immigrants.

Her rulings mean Republicans will need to remove the provisions from the budget reconciliation package, modify them into compliance with the Byrd Rule or bring the legislation to the floor as is and face a budget point of order that requires 60 votes, and thus Democratic support, to waive.

Republicans have rewritten other provisions that the parliamentarian ruled against and are likely to attempt to do so here. The need to rewrite major pieces of the bill will likely delay their plans to begin the floor process as soon as Friday.

If the GOP is unsuccessful in bringing the health care provisions into compliance, it will result in more than $250 billion in cuts being struck from the bill, according to Mr. Wyden.

“Republicans are hellbent on using the reconciliation process to capture ideological trophies that will leave Americans worse off and fly in the face of their self-proclaimed commitment to states’ rights,” he said. “The parliamentarian has rightly pointed out that many of those policies do not belong in reconciliation.”

The health care rulings on the Senate Finance section of the bill follow a series of decisions from the parliamentarian finding a handful of provisions in each committee’s portion of the bill that violate the Byrd rule.

In the Senate Health, Education, Labor and Pensions Committee’s bill, Ms. MacDounough ruled against several provisions seeking to reform federal student loan programs and a provision prohibiting federal cost-sharing reduction payments to qualified health plans that cover abortion services.

“This effort was part of Republicans’ plan to institute a backdoor nationwide abortion ban by making abortion care inaccessible for everyone, everywhere,” said Sen. Patty Murray, Washington Democrat. “Democrats challenged this attack on women’s health care under Senate rules and won — and we will keep fighting every Republican attempt to rip away abortion access every way we can.”

• Lindsey McPherson can be reached at lmcpherson@washingtontimes.com.