Updated 8:37 p.m. | The House Republican leadership’s legislation to partially repeal and replace the 2010 health care law would reduce the deficit by $337 billion over a decade while increasing the number of uninsured by 24 million people by 2026, the Congressional Budget Office estimated Monday.

The nonpartisan budget scorekeepers predicted that under the House GOP plan — which was scheduled for consideration by the House Budget Committee on Thursday to be packaged as a reconciliation bill that would only require a majority to pass in the Senate —  the biggest savings would come as a result of decreased funding to Medicaid and cutting off subsidies for individuals to purchase insurance on the health care exchanges. It would also lower average premiums enough to stabilize the individual health insurance market, according to the “score” of the legislation.

The CBO, working with the Joint Committee on Taxation, estimated that by 2018, 14 million more people would be uninsured than under the current law. That figure would rise under the proposed legislation to more than 24 million by 2026. Compared to current law estimates, that would translate to more than 52 million Americans without health insurance by that year.

The CBO score will generally come as welcome news to Republicans, who have said in recent days that the primary goal of their health care overhaul is to lower costs and stabilize the market rather than to reduce the number of people without health insurance.

The estimate showing that the legislation would reduce, not add, to the deficit will also be something Republicans can get excited about.

House Speaker Paul D. Ryan was quick out of the gate with a statement commending the report for estimating that the GOP plan will lower costs and premiums.

“CBO also finds that this legislation will provide massive tax relief, dramatically reduce the deficit, and make the most fundamental entitlement reform in more than a generation,” the speaker said.

House Budget Chairwoman Diane Black defended the bill for achieving its goal of reducing health care costs.

“Dismantling the individual mandate gives Americans the freedom to make choices for themselves, even if that choice is to not have health care coverage,” the Tennessee Republican said in a statement.

But Democrats have and will continue to hammer the GOP over the legislation’s effect on insurance coverage. The CBO prediction that 52 million people would be uninsured by 2026 under the GOP legislation, compared to 28 million who would lack insurance under current law, provides the minority party with a ready-made comparison.

In a statement issued within minutes of the report’s release, House Ways and Means ranking member Richard E. Neal and Energy and Commerce ranking member Frank Pallone Jr. panned the bill as “a major step backwards” that guts Medicaid and pulls billions of dollars from Medicare to pay for tax cuts for the wealthy.

“Today’s CBO report now confirms what we already knew: Despite promises that ‘everyone would be covered’ and ‘no one would be worse off,’ this Republican bill would rip away health insurance from 24 million Americans over the next decade and ask millions to pay more for less coverage,” they said. “Despite warnings from independent experts like CBO and others, Republicans continue to recklessly jam this bill through Congress without so much as a single hearing on what effects their plan will have on middle-class families.”

The Capitol’s top two Democrats said the report should cause pause, with House Minority Leader Nancy Pelosi saying Republicans should abandon the measure.

“I would hope that they would pull the bill. It’s really the only decent thing to do,” the California Democrat said, adding that the loss of 24 million people’s insurance was simply cruel.

Senate Minority Leader Charles E. Schumer, appearing alongside Pelosi at a press availability Monday afternoon, said the CBO report “should be a knockout blow to the Republicans in Congress,” 

Schumer predicted Senate Republicans concerned about loss of coverage and the effects on issues like opioid abuse treatment, as well as qualms from conservatives who don’t think the bill goes far enough would be enough to scuttle the measure.

“I think [Senate Majority Leader Mitch McConnell] is going to have real difficulty,” the New York Democrat said.

Indeed, Maine Republican Sen. Susan Collins described the projections on loss of health insurance coverage as cause for concern.

“The top line numbers are alarming,” she said.

Sen. Lindsey Graham suggested that revisions will be needed to the GOP House bill in the wake of the CBO score. “We should pause and try to improve the product,” the South Carolina Republican told reporters Monday.

The White House and congressional Republicans had been pre-emptively casting doubt on the accuracy of the CBO’s predictions. In a press briefing before the report’s release Monday, White House Press Secretary Sean Spicer criticized the CBO, saying that “they were way off” on their cost estimates for the 2010 health care law. He added that the White House wants lawmakers to remember that as they consider the office’s coming projections for a GOP replacement plan.

Health and Human Services Secretary Tom Price criticized the CBO for not scoring other aspects of the GOP’s “three-pronged approach” that includes regulatory actions and future legislation. The CBO can only score legislation that has been introduced, and the regulatory actions have not been unveiled yet either. As a former House Budget chairman, Price is likely to know how the CBO operates.

“We disagree strenuously with the report that was put out. We believe that our plan would cover more individuals at a lower cost, and give them the choices that they want for the coverage that they want for themselves and their family — not that the government forces them to buy,” Price said.

The CBO estimated the previous 2015 repeal bill that President Barack Obama vetoed last year, which did not include any policies to replace the health care law, would cut the deficit by $516 billion. Several conservative Republicans, like Sen. Rand Paul of Kentucky and many members of the House Freedom Caucus, want a vote on that repeal legislation again.

But that estimate included the effects of a dynamic analysis showing the legislation would increase economic growth and produce more tax revenues. The agency said it has not had time to prepare a dynamic score of the current legislation.

John T. Bennett, Niels Lesniewski and Kerry Young contributed to this report.