The Tax Policy Center reported Monday that the House Republican bill would raise taxes on families throughout the income distribution. But it withdrew its findings after discovering the error.
The report had provided fodder for the tax legislation's Democratic opponents. Congressional Republicans and the Trump administration have criticized the nonpartisan nonprofit group as biased.
"It’s no wonder Republicans are trying to rush this bill through – the more scrutiny it gets, the worse it looks," Senate Democratic Leader Charles Schumer of New York said in a statement on the analysis.
Republicans have said that the bill is meant to lower everyone's taxes.
The Tax Policy Center reported that the bill would cut the average taxpayer's bill by $1,100 and that taxes would drop for every income group.
Nevertheless, many individuals would see tax increases, the group estimated, including high earners in high-tax states who would lose out from the GOP's plan to eliminate the deduction for state and local taxes.
"We are overestimating the number of taxpayers that would see a tax cut and underestimating the number of taxpayers that would see a tax increase," the report read.
The brief analysis also found that the top 1 percent, those making more than $730,000 in the think tank's metric, would see an average cut of $37,000 in 2018, or 2.5 percent of after-tax income.
People in the middle fifth of the income distribution would get a tax cut of $700, about 1.2 percent of after-tax income.
For the bottom fifth, the corresponding figures would be $40 and 0.3 percent of after-tax income.