WASHINGTON — The GOP plan to replace the Affordable Care Act would cause 24 million Americans to lose health coverage over the next decade, according to an official government analysis released Monday that greatly complicates President Trump’s promise to scrap his predecessor’s signature achievement.
The report by the nonpartisan Congressional Budget Office underscores the major disruption the Trump administration and the Republican-controlled Congress would inflict on America’s health care markets, quickly reversing Democrats’ strides toward universal health care.
The GOP House replacement bill would increase the percentage of uninsured Americans under age 65 to 19 percent by 2026, up from 10 percent if the Affordable Care Act were left intact, according to the CBO analysis.
Low-income people age 50 to 64 would bear the greatest burden of lost insurance, the CBO said. Administration officials quickly dismissed the findings as “not believable.’’
For fiscal hawks, there is something to cheer: Cuts in subsidies for low- and moderate-income families and Medicaid programs would help reduce deficits by $337 billion over 10 years. But those savings would result in lost gains in insurance coverage.
Democrats roundly faulted the plan, and even some Republicans were wary.
“The CBO estimate that millions of Americans could lose their health insurance coverage if the House bill were to become law is cause for alarm,” said Senator Susan Collins of Maine, a Republican. “It should prompt the House to slow down and reconsider certain provisions of the bill.”
About 14 million would lose insurance by next year, the CBO estimated. Most would stop buying health insurance, because the Republican plan would remove the requirement that residents obtain coverage, according to the estimates. Also, government subsidies would be scaled back in favor of a system of less generous tax credits, making it more costly to buy insurance. Millions more would lose insurance because of deep cuts to Medicaid programs, the CBO said.
Most of the damage would be done in the first four years, as 21 million people would lose insurance by 2020, Trump’s reelection year. About 7 million would lose employer-based insurance by 2026, according to the estimate.
Premiums for subsidized insurance would spike 15 percent to 20 percent in the next two years, because the healthiest people would stop buying insurance, leaving sicker people in the remaining insurance pool, the CBO added.
The CBO analysis presented Trump and House Speaker Paul Ryan, a key architect of the plan, with bad news. They already are facing universal Democratic opposition, scorn from conservative Republicans, and deep skepticism from some GOP senators.
The administration immediately disputed specific findings. Health Secretary Tom Price said the House bill would cover more individuals — not fewer — while lowering costs.
Price said the administration disagrees ‘‘strenuously’’ and that the CBO report is “just not believable.’’
“The fact of the matter is [consumers] are going to be able to [buy] a coverage policy that they want for themselves and for their family. They are going to have the kind of choices that they want. . . so we think that CBO simply has it wrong,” Price said.
Democrats seized on the dissonance between the analysis and GOP promises on what their replacement for the Affordable Care Act would mean for the country.
“Tens of millions will lose their coverage, and millions more, particularly seniors, will have to pay more for health care,” Senate minority leader Chuck Schumer said. “The CBO score shows just how empty the president’s promises, that everyone will be covered and costs will go down, have been.”
“Throwing 24 million people off their health care to give billionaires a tax break is heartless & irresponsible. We cannot pass #Trumpcare,” tweeted Senator Elizabeth Warren of Massachusetts.
The report’s findings seemed to open a stark gap between Trump’s health care promises and the reality of the legislation he says he supports.
“We’re going to have insurance for everybody,” Trump promised in January.
He also repeatedly promised on the campaign trail that he would not cut Medicaid, the federal insurance program for the poor. But the CBO analysis says the House GOP bill, which fundamentally transforms how the federal government reimburses states for the program, would slash $880 billion in federal spending from Medicaid programs over 10 years.
Ryan quickly defended the legislation.
“Our plan is not about forcing people to buy expensive, one-size-fits-all coverage. It is about giving people more choices and better access to a plan they want and can afford,” he said in a statement.
But changes likely will be required to win over Republicans in the Senate.
“Let’s say the CBO is half-right; that should be cause for concern,’’ said Senator Lindsey Graham, a South Carolina Republican. “So rather than attacking the CBO as the exclusive way of moving forward, I would think the prudent thing for the party to do is to look at the CBO report and see if we can address some of the concerns raised.”
The CBO estimates that premiums for single policy holders in the nongroup market would be 15 percent to 20 percent higher under the bill for 2018 and 2019. By 2026, however, the office estimates that those same premiums would be about 10 percent lower than under the Affordable Care Act.
Among the hardest-hit would be moderate- and low-income seniors between the ages of 50 and 64, who would make up a disproportionately large share of the group that would lose insurance under the GOP bill, the CBO said. That is due to several related changes in the bill, including provisions that allow insurers to charge older Americans far more than the Affordable Care Act does.
The current health law subsidizes consumers to help people pay for insurance in the marketplace. The GOP bill would replace those direct subsidies —
Two of the most popular parts of the Affordable Care Act would be preserved — the ability of children to stay on their parents’ insurance until age 26, and banning insurers from discriminating against people with preexisting conditions.
Major groups representing hospitals and doctors, including the American Medical Association, have come out in opposition to the House bill. So has AARP, the powerful seniors lobby that boasts close to 38 million members. It already has an ad on the Web bashing the House bill for amounting to an “age tax.” A flannel-shirt wearing actor takes a break from chopping wood to describe the bill as “overcharging older Americans for their health insurance while lining the insurance industry’s pockets.”
Republicans can’t even count on much support from their usual allies. Numerous conservative groups have skewered the bill, including Americans for Prosperity, FreedomWorks, and Heritage Action, an advocacy group that is a sister group to the Heritage Foundation, a conservative think tank that has otherwise been closely allied with the Trump administration.
Correction: An earlier version of this story misstated the time period over which federal deficits will reduce.