If the bill is passed, the GOP will get one step closer to repealing and replacing Obamacare, a goal set by Republicans when the Affordable Care Act took effect seven years ago. And President Donald Trump himself called the House bill "mean" - though he's lent his support to the Senate version and is lobbying for passage. It looks like this.
The federal government would save billions, mostly by making deep cuts to Medicaid.
How significant is this?
As Democrats have united in opposition to the draft, Republican leaders have struggled to rally enough support from within their ranks to get the bill over the line. He did not mention the number of people who would not have health care coverage.
The House passed its own version of a health care bill in May.
In unusually harsh terms, a conservative Republican senator accused party leaders Monday of trying to rush the party's health care bill through the Senate in remarks that underscored the challenge they face in staunching a rebellion among GOP lawmakers.
Senate Majority Leader Mitch McConnell has been pushing for a vote on the plan before the July 4 recess but some on Capitol Hill say that's too soon.
Also, senators would eliminate the mandates that require almost all Americans to have coverage and companies with more than 50 workers to provide health benefits. The CBO estimates that 22 million people would lose coverage in the next decade, with 15 million losing coverage in the first year. Susan Collins, R-Maine, and Lisa Murkowski, R-Alaska, have said the CBO's uninsured numbers will be important in how they decide whether to support the bill or not. Johnson called leadership's effort "a little offensive" and said conservatives had no input into the package.More news: GOP senator to block arms sales over crisis with Qatar
Collins, who had raised "very serious concerns" about the bill before the report's release, said Monday that she wants to work with Republicans and Democrats to "fix the flaws" in the Affordable Care Act.
Already, an amendment has been added since the legislation was unveiled last week, a provision would lock people out of buying insurance for six months if they lacked coverage for more than about two months in the prior year. The personal health insurance marketplace is estimated to remain largely stable, and premiums will go down (after a spike next year). The analysis also offers clarity to wavering Senate Republicans on whether to vote for the bill later this week. The Senate plan would phase out extra federal money 31 states receive for expanding Medicaid to additional low-income earners, and put annual caps on overall Medicaid money the government until now has automatically paid states, whatever the costs.
And senators would keep more of Obamacare's insurance regulations than the House legislation, while allowing insurers to charge more to older policyholders.
The original Senate bill had dropped the Obamacare penalty on those who do not have insurance.
Meanwhile, a nonpartisan coalition of patient and consumer groups - American Cancer Society Cancer Action Network and the March of Dimes among them - urged senators to vote against the bill, saying it "will do irreparable harm to patients, particularly those living with chronic illnesses".
Trump has criticized the insurance now offered in the exchanges - not only for sky-high premiums, but also because "deductibles are so high that it is practically useless".
The budget office writes that, "The largest savings would come from reductions in outlays for Medicaid - spending on the program would decline in 2026 by 26 per cent in comparison with what CBO projects under current law", also known as Obamacare.