Repealing Obamacare’s individual mandate would increase the number of uninsured people by 13 million by 2027, the Congressional Budget Office said in a new estimate Wednesday.

Earlier this month, the White House and some in Congress briefly floated that they would try to repeal the individual mandate as part of Republicans’ tax cut proposal. The idea landed with a thud. Republicans in both chambers have repeatedly attempted to pass legislation to erase former President Barack Obama’s signature legislative achievement, to little avail and increasing frustration from the Trump administration.

According to the CBO, repealing the individual mandate would save $338 billion between 2018 and 2027. Four million more people would be uninsured by 2019 as a result of the mandate’s repeal, the CBO said.

The CBO further estimated that a mandate repeal would increase premiums 10 percent “in most years” of the following decade, relative to the office’s baseline projections.

The non-partisan office, whose analyses of the effects of Republicans’ Obamacare repeal efforts have come under partisan attack in recent months, said the estimate was not based on specific legislative language, but rather on the prospect of simply removing penalties for individuals without insurance coverage who are not exempt from the mandate under the current law.

The analysis was completed alongside the staff of the Joint Committee on Taxation, the CBO said.