When the Congressional Budget Office releases its findings on the Republicans' health-care bill, it will predict that 15 million people are going to lose coverage, Brookings Institution fellow Matt Fielder told CNBC on Friday.
President Donald Trump and Republican lawmakers have said replacing Obamacare is their first priority. The GOP bill is currently making its way through Congress and has yet to be scored by the CBO.
"There are sort of three major components of this legislation that would lead to significant losses in coverage. One is substantial reductions in funding for state Medicaid programs. Second is repealing the individual mandate. And the third is a variety of other changes to private health insurance markets," Fielder, who co-authored the Brookings report on its findings, said in an interview with "Closing Bell."
The think tank's estimate is for 2026, which is the end of the CBO's 10-year window that it uses in its evaluation.
Some have been trying to cast doubt on the nonpartisan CBO.
Earlier this week, White House press secretary Sean Spicer said, "If you're looking at the CBO for accuracy, you're looking in the wrong place."
He added, "I mean they were way, way off the last time in every aspect of how they scored and projected Obamacare.
— The Associated Press contributed to this report.