Of particular concern for GOP backers of the American Health Care Act is the CBO’s projection for its immediate impact. If enacted soon, an estimated 14 million people would drop their insurance next year because the proposal repeals the tax penalties associated with the individual mandate, the CBO forecasts. If people are not required to buy insurance, in other words, many will stop doing so. Millions more would join the ranks of the uninsured after 2020, when the bill would roll back the expansion of Medicaid under the Affordable Care Act. Conservatives have called for repealing the expansion sooner, which would likely result in more people dropping coverage in the first years after enactment.

Republicans have assailed the increase in premiums in some markets under Obamacare, but the CBO offered a mixed review of their proposal on that count. Premiums would, on average, drop by 10 percent for people on the individual market over the next decade, but not before they rose sharply in the first two years. That short-term pain could make for a difficult sell for Republican lawmakers up for reelection in 2018, who would have to preach patience to their constituents who face higher insurance bills. And after years of criticizing Democrats for cutting $700 billion from Medicare to pay for the Affordable Care Act, Republicans would have to defend a proposal that not only maintains those cuts but chops another $880 billion from Medicaid, according to the CBO. Those cuts offset the repeal of nearly $900 billion in tax increases on wealthy people and businesses in Obamacare.

The Republican bill could not increase the deficit in order to pass muster under the budget reconciliation rules they want to use to pass it. And the CBO found that the proposal would slash the budget gap by $337 billion over a decade, as the cuts to Medicaid and insurance subsidies more than make up for the bill’s tax cuts.

With the new projection, congressional Republicans are sure to face more accusations that the bill breaks President Trump’s promise of “insurance for everybody” and the party’s explicit vow that its replacement would “decrease premiums.” Monday’s report prompted a split reaction from House Speaker Paul Ryan and Tom Price, his former congressional ally who is now secretary of health and human services. Ryan highlighted the findings favorable to Republicans and embraced the report overall. “I’m excited by this analysis,” he said Monday evening on Fox News, pointing to the longterm drop in premiums and CBO’s forecast that the individual health insurance market would stabilize over time if the bill became law. “It actually exceeded my expectations.”

Price, however, denounced the findings.

“We disagree strenuously with the report that was put out,” he told reporters outside the White House. “We believe our plan will cover more individuals at a lower cost and give them the choices that they want for the coverage that they want for themselves and for their family.” Price in particular disputed the forecast that 14 million people would go uninsured next year, a figure that he noted was greater than the number of people currently enrolled in Obamacare exchanges. “It’s just not believable,” he said. “We think that CBO simply has it wrong.”