CBO's analysis, released Tuesday, found that the bulk of increases in the number of uninsured people — by 18 million — would come in the the first full year following enactment. In that year, the report said, "about half of the nation's population [would live] in areas that would have no insurer participation" in the individual market.
That analysis found that the number of uninsured would jump to 27 million as a result of the elimination of Obamacare subsidies, along with funding that has expanded Medicaid benefits to millions of poor adults.
The number of uninsured as a result of repeal would grow to 32 million by 2026, with about three-quarters of the population living in areas with no insurers selling individual plans, according to the CBO report, which was prepared at the request of Democratic leaders in the Senate.
That number of uninsured due to repeal exceeds by 12 million the number of people who have become insured as a result of ACA over the past six years.
In the first year of repeal, according to the report, premiums in the individual market "would increase by 20 percent to 25 percent — relative to projections under current law," the CBO said.
"The increase would reach about 50 percent in the year following the elimination of the Medicaid expansion and the marketplace subsidies, and premiums would almost double by 2026," according to the report.
The findings reflect CBO's view that insurers would exit the individual health plan market as subsidies disappeared and as fewer customers sought coverage.
A spokeswoman for House Speaker Paul Ryan, R-Wis., called the CBO's projection "meaningless, as it takes into account no measures to replace the law nor actions that the incoming administration will take to revitalize the individual market that has been decimated by Obamacare."
Ryan has said that Obamacare is in a "death spiral," which in the insurance industry refers to customers fleeing plans as prices rise, leading to an exodus of more customers and increasing premiums to offset the losses of the customer base.
The Obama administration has denied that the individual insurance market is in a death spiral, pointing to the fact that signups in plans sold on Obamacare exchanges during the ongoing enrollment season has outpaced last year's levels.
The CBO report was issued on the same day as the release of an NBCNews/Wall Street Journal survey that found Obamacare has never been more popular.
A total of 45 percent of respondents to the poll said they believed Obamacare is a good idea, the highest percentage since the NBC/WSJ poll began asking that question in April 2009, and the first time the number of people positive about the law outnumbered those who hold a negative view of it. Forty-one percent in the new poll said they believed Obamacare is a bad idea.
Half of Americans said they had little or no confidence that GOP proposals to replace the Affordable Care Act will be an improvement.