Team Trump is studying a plan to cut capital gains taxes by $100 billion over 10 years by factoring in inflation, it was reported Monday.

Treasure Secretary Steven Mnuchin said in an interview on the sidelines of the Group of 20 summit meeting in Argentina earlier this month that his department was studying whether it could issue regulations on its own — without going to Congress — to allow Americans to account for inflation in determining capital gains tax liabilities, The New York Times reported.

Treasury could redefine “cost” for calculating capital gains, allowing taxpayers to adjust the initial value of an asset, such as a home or a share of stock, for inflation when they sell them.

“If it can’t get done through a legislation process, we will look at what tools at Treasury we have to do it on our own and we’ll consider that,” Mnuchin told the paper, saying he wasn’t sure that his department had the authority to act alone.

“We are studying that internally, and we are also studying the economic costs and the impact on growth.”

Capital gains taxes are determined by subtracting the original price of an asset from the price at which it was sold and taxing the difference, usually at 20 percent.

If someone spent $100,000 on a stock in 1980 and sold it for $1 million today, he or she would owe taxes on $900,000.

But if the original purchase price was adjusted for inflation, it would be about $300,000, reducing the taxable gain to $700,000, saving the investor $40,000.

The move would likely court challenges and fuel Democrats’ arguments that the GOP cares only about making the rich richer.

President George H.W. Bush’s administration rejected a similar move in 1992 after concluding that Treasury didn’t have the power to make the change unilaterally.

“At a time when the deficit is out of control, wages are flat and the wealthiest are doing better than ever, to give the top 1 percent another advantage is an outrage and shows the Republicans’ true colors,” Sen. Chuck Schumer told The Times.

“Furthermore, Mr. Mnuchin thinks he can do it on his own, but everyone knows this must be done by legislation.”

Capital gains taxes are virtually all paid by the wealthiest Americans, and they were left unchanged in the $1.5 trillion tax law that Trump signed last year.

Liberal economists said they saw little benefit in it beyond another giveaway to the rich.

“It would just be a very generous addition to the tax cuts they’ve already handed to the very wealthy,” Alexandra Thornton, senior director of tax policy at the liberal Center for American Progress, told the paper.

But some Republicans were gung-ho, saying the change would produce a windfall for the government as stock sales boom.

“I think we ought to look at not penalizing Americans for inflation,” said Rep. Kevin Brady of Texas, the Republican chairman of the Ways and Means Committee.