Repealing Obamacare’s individual mandate would save the government $338 billion over a decade and result in 13 million more uninsured Americans in 2027, according to a new CBO score.

Congressional Republicans are considering axing Obamacare’s requirement that most Americans obtain health coverage as part of a tax reform package, although there is resistance from GOP leaders who fear the provision would be rejected in the Senate because it would also mean millions in coverage losses and revive the partisan debate on the rest of the Affordable Care Act.

The CBO score was based on prior legislative text to repeal the mandate, not on new language related to tax reform.

The new analysis finds that repealing the mandate would not have as big of an impact as the estimates CBO made nearly a year ago. A December 2016 CBO analysis found that undoing the mandate would reduce the budget deficit by $416 billion over nearly a decade and result in 15 million more uninsured Americans in 2026 than under current law.