What's in the Trump tax plan that promises 'massive' cuts

— -- The White House unveiled a sweeping tax reform plan on Wednesday that calls for dramatically cutting federal taxes for businesses and simplifying rules for individuals.

The blueprint would slash corporate taxes to 15 percent for large and small businesses, as well as consolidate categories for individual taxes, lowering the top bracket from nearly 40 percent to 35 percent.

Experts interviewed by ABC News largely agreed that the drastic tax cuts proposed by Trump would significantly reduce federal revenue and balloon the federal deficit. One analysis, by the bi-partisan Committee for a Responsible Federal Budget estimates the Trump’s plan could cost anywhere between 3 and 7 trillion dollars in lost revenue over the next decade. Experts also said the broad brushstrokes of the new White House plan lack the necessary detail on the issue's more complex and controversial questions.

Gary Cohn, the White House's chief economic adviser, said the proposed reduction would be "one of the biggest tax cuts" in U.S. history. "We have a once-in-a-generation opportunity to do something really big," he said at a White House press briefing.

"Under the Trump plan, we will have a massive tax cut for businesses," said Treasury Secretary Steve Mnuchin, echoing the Trump campaign's promise to slash the corporate tax rate to 15 percent. The current federal corporate tax rate ranges from 15 percent to 35 percent, according to the Government Accountability Office.

The new plan would consolidate tax brackets for individuals into three rates: 10 percent, 25 percent and 35 percent. There are currently seven brackets for individuals, peaking at just shy of 40 percent. Also, the plan would double the standard deduction, meaning that a married couple would pay no taxes on the first $24,000 earned in a year.

The wide-ranging tax reform blueprint, distributed to reporters today on just one page, contains many of the same ideas that Trump campaigned on before the 2016 election but does not include the many intricate details needed to make accurate budget projections, experts say.

Critics of the plan say it would cause a problematic loss in revenue for the federal government. One independent analysis by the Urban-Brookings Tax Policy Center found that the plan could result in a $6 trillion shortfall over the next decade, which experts say would add to the deficit and national debt.

And the plan faces an uphill climb in Congress, where Republicans must win some Democratic cooperation to bring the plan to a vote in the Senate. A statement from Republican leaders in Congress said Trump's plan will "serve as critical guideposts from Congress and the administration as we work together" on a tax reform package.

Still, the White House maintains that economic growth resulting from the tax cuts will make up for the lost dollars. "This will pay for itself with growth and with reduction of different deductions and closing loopholes," said Mnuchin.

Marc Short, the White House director of legislative affairs, said the the Trump administration was "not looking to propose a tax system that ends up adding to deficit."

"Our expectation is that with the growth we create and the elimination of many deductions, that we will make it revenue neutral," he told ABC News' political director Rick Klein and chief White House correspondent Jonathan Karl on "Powerhouse Politics."

The plan calls for repealing the alternative minimum tax, which affects high-income Americans who take lots of deductions. Returns from 2005 showed that most of Trump's tax liability that year was due to the AMT.

The blueprint would eliminate all personal tax deductions other than for mortgage interest and charitable giving. It would also eliminate the estate tax, which critics call the death tax.

The largest deduction that could be eliminated is for state and local income taxes, which allows people to deduct those taxes from their federal income tax bill. Ending that deduction would especially affect blue states — like New York, California and Massachusetts — which tend to have high local and state income taxes. Other smaller itemized deductions people often take that could be eliminated under the Trump plan include those for medical expenses, casualty losses, college loan interest and unreimbursed job expenses.

Administration officials are calling this a first draft — an outline of priorities and principles. In the final hours before its release, some key parts were still a work in progress.

ABC News' Lauren Pearle and Zunaira Zaki contributed to this report.