Extending the expiring provisions in Trump’s tax cuts is slated to cost more than $4 trillion by 2028, the organization noted in its analysis published Thursday, citing current Joint Tax Committee and Congressional Budget Office projections.

That’s compared to around $3 trillion when the law was passed, marking an increase of roughly 33 percent, more than what would be expected from growth in the economy and inflation alone, the report argues.

“While inflation and economic growth explain some of the difference, the costs of the tax cuts as a share of GDP have increased by about 30 percent (0.3 percentage points) since 2018,” budget researchers said.

The reason for the deficit boost isn’t immediately clear, but the CRFB said it could be due to tax evasion on one of the revenue expanders in the 2017 law, as well as abuse on the Trump pass-through deduction.

“Increased investment in equipment and tax avoidance efforts involving [state and local tax] cap workarounds and abuse of the 20 percent pass-through deductions have clearly played a role,” the researchers wrote.

The Hill’s Tobias Burns has more here.