The Congressional Budget Office estimated that 14 million people would lose health insurance by 2018 under House Republicans' health care plan. That number would increase to 24 million by 2026.
"Most of that increase would stem from repealing the penalties associated with the individual mandate," officials said in their report, released Monday.
But the plan will decrease the federal deficit by $337 billion by 2026, according to the report.
The CBO estimates that insurance premiums will go up by about 15 to 20 percent on average in 2018 and 2019, but then will drop after 2020.
By 2026, the CBO estimates premiums will be roughly 10 percent lower than they are under current law.
The report cautioned that the average estimate on premium costs would vary widely based on patient age.
"Under the legislation, insurers would be allowed to generally charge five times more for older enrollees than younger ones rather than three times more as under current law, substantially reducing premiums for young adults and substantially raising premiums for older people," the report said.
The report also states that the tax credits in the American Health Care Act would hurt lower income people, especially elderly people, and benefit wealthy Americans.
House Speaker Paul Ryan immediately praised the estimates.
Democrats were quick to blast the plan.
In anticipation of the report, GOP lawmakers and the White House have dismissed the CBO's accuracy.
White House Spokesman Sean Spicer last week said "if you’re looking to the CBO for accuracy, you’re looking in the wrong place.”
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