By Stephanie Armour and Kristina Peterson 

The Senate Republican health-care overhaul would result in 22 million more people uninsured and cut the cumulative federal deficit by $321 billion in the next decade compared with the current Affordable Care Act, according to an estimate released Monday by the Congressional Budget Office.

That assessment comes as Senate Majority Leader Mitch McConnell (R., Ky.) is engaged in last-minute negotiations with more than a half-dozen GOP lawmakers wavering in their support of the bill. Sen. Susan Collins (R., Maine) immediately came out against the bill, citing the CBO report and raising the specter that the monthslong push to overhaul health care could collapse on a procedural vote.

GOP leaders have said the Senate will vote this week on the bill. They can lose no more than two Republican senators on either the "motion to proceed" to debate on the bill, which could come as early as Tuesday, or on the bill itself, scheduled for a vote later in the week. None of the 48 Senate Democrats is expected to vote in favor of the bill.

Six GOP senators are now opposed to the bill and at least three have said they would block it on the procedural vote.

The bill's effect on consumers would vary widely, the CBO found. Many people would see lower premiums, partly because their plans would cover fewer benefits. But for lower-income consumers or those with special needs, medical costs could be significantly higher.

Republicans emphasized the CBO's finding that after rising for a time, average premiums would go down after 2020.

"Our plan will help address Obamacare's ballooning costs for consumers by lowering premiums over time and cutting taxes, and today's estimate confirms that," said Sen. John Cornyn of Texas, the second-ranking Senate Republican.

The White House said in a statement: "The CBO has consistently proven it cannot accurately predict how healthcare legislation will impact insurance coverage. This history of inaccuracy, as demonstrated by its flawed report on coverage, premiums, and predicted deficit arising out of Obamacare, reminds us that its analysis must not be trusted blindly."

Democrats and their allies pounced on the analysis to say the Senate bill would gut Medicaid and give tax breaks to the wealthy. "Today's report confirms what doctors, patient advocates, Democrats and Republicans have been saying for weeks: Trumpcare will lead to higher costs for less care, and will lead to tens of millions of Americans left without health insurance," said Senate Minority Leader Chuck Schumer (D., N.Y.).

Senate leaders have been working for weeks in closed-door sessions to draft a bill knocking down key parts of the ACA and replacing it with a new system of tax credits and cuts to Medicaid. If the bill passes this week, it is possible the House could vote on health-overhaul legislation before Congress takes a recess in August.

Four conservative Republicans -- Sens. Rand Paul of Kentucky, Ron Johnson of Wisconsin, Mike Lee of Utah and Ted Cruz of Texas -- said shortly after the bill's release they opposed it in its current form. A centrist, Sen. Dean Heller (R., Nev.), announced his opposition the following day.

Ms. Collins said in a trio of tweets Monday evening that while she wanted to fix the ACA, the "CBO analysis shows Senate bill won't do it," citing the cuts to Medicaid funding and how that could restrict health-care access in rural areas. "Senate bill doesn't fix ACA problems for rural Maine," she said.

Mr. McConnell's most immediate challenge is securing the 50 votes needed to clear a procedural hurdle expected Tuesday or Wednesday. Mr. Paul and Ms. Collins have said they will vote against it, and Mr. Johnson has said he couldn't vote to advance the bill without further information.

If Mr. McConnell can't persuade at least one of those Republicans to change their mind, the months-long push to overhaul the ACA would collapse on the procedural vote.

Lawmakers will have several days to digest the CBO analysis, if the vote occurs this week as planned. When the CBO reported that the House version of the bill would result in 23 million fewer insured Americans in 2026 than the ACA, it delivered a jolt that undermined the bill's support, though House Republican leaders were able to muster enough support to narrowly pass it.

It is unclear if the CBO score will have a similar effect in the Senate. Some GOP centrists had expressed concerns that the bill would leave too many people uninsured.

The increase in the uninsured would be disproportionately larger among older people with lower income, particularly people between 50 and 64 years old, according to the CBO.

Under the Senate bill, an estimated 49 million people would be uninsured by 2026 compared with 28 million who would lack care under the ACA, according to the analysis by CBO and the Joint Committee on Taxation. That's primarily because of sizable cuts to the Medicaid program, the end of a penalty for not having coverage, and substantially smaller subsidies to help low-income people purchase insurance. The number of Medicaid enrollees under 65 would fall by about 16% by 2026 relative to current law (or 15 million fewer people).

The Senate bill would phase out enhanced federal funding by 2024 to the 31 states that expanded Medicaid under the ACA, and it would alter the program's overall funding in a way that would sharply limit the money received by the states.

Federal spending on Medicaid would be reduced by $772 billion over 10 years under the Senate bill, compared with $834 billion under the House bill, according to the CBO.

States could use waivers to roll back the ACA's requirements that insurers cover certain benefits, such as maternity care and mental-health services, and could use waivers to override the ACA's limits on out-of-pocket and lifetime medical costs.

The CBO estimated that about half the country's population would live in states that choose to use waivers that give insurers leeway to cover fewer services required by the ACA. Residents of those states who sought benefits that insurers no longer must cover would face "substantial increases" in their costs, the CBO said.

Republicans say the legislation is needed because the individual insurance markets under the ACA are struggling. About 47 counties in the U.S., or about 34,000 people, are at risk of having no insurer to pick from on the exchanges next year, according to an analysis by the Kaiser Family Foundation.

On Monday, Anthem Inc. said it believes that Senate bill will bolster the individual market, an endorsement that comes as many other insurers have suggested the legislation could undermine the ACA marketplaces.

Anthem said it believed the bill "will markedly improve the stability of the individual market and moderate premium increases" because it allots billions to help stabilize the markets, eliminates a tax on health insurance plans and works on "aligning premium subsidies with premium costs."

The bill's reduction of the federal deficit by $321 billion through 2026 is more than the House version, which the CBO estimated would curb the deficit by $119 billion. Under Senate procedural rules, the bill must have at least as much of a deficit reduction at the legislation passed by the House. That leaves Senate Republican leaders with about $200 billion they can add to the bill to get more lawmakers to support the legislation and still meet the same savings as the House version.

Mr. Trump met over the weekend with more than a half-dozen Senators, the White House said.

The bill is widely expected to be tweaked before any vote this week in an effort to woo reluctant Republican lawmakers into supporting the legislation.

Republican leaders remained optimistic Monday that they could iron out differences among GOP senators, including by adding funding for opioid treatment that was being sought by several centrist Republicans and a potential amendment from Sen. Ted Cruz of Texas that would allow insurers to offer lower-priced plans that offered fewer benefits under certain circumstances.

One possibility to secure the vote of Sen. Lisa Murkowski of Alaska was an adjustment to the Medicaid funding formula for her state, a senior White House official said, adding that Alaska's uniquely high costs and large geography could justify such a move in the face of criticisms that the bill included state-specific "kickbacks."

--Natalie Andrews and Richard Rubin contributed to this article.

Write to Stephanie Armour at stephanie.armour@wsj.com and Kristina Peterson at kristina.peterson@wsj.com

(END) Dow Jones Newswires

June 26, 2017 20:16 ET (00:16 GMT)