Trump administration officials and congressional Republican leaders are negotiating the terms of a tax reform bill. While they have not introduced legislation or a detailed plan, here's what we know about their goals and possible intentions from what they have said so far, including their joint statement.
The GOP vision tax reform consists of two parts: The first is lowering tax rates and eliminating taxes. That leads to lower tax revenue. The second part is eliminating tax breaks, which raises revenue.
Lowering the corporate tax rate
THE PLAN: Under current law, the corporate tax rate is 35 percent, the highest among rich countries.
President Trump has called for lowering it to 15 percent. House Republicans have set a goal of 20 percent. As a group, they have not set a specific target.
WHO BENEFITS: Economists disagree about whether corporate tax cuts mostly benefit shareholders or workers. Treasury Secretary Steven Mnuchin has said that 70 percent of the corporate tax cut would flow to workers, a claim with some support in research by scholars at the American Enterprise Institute. The Congressional Budget Office, however, assumes that only 25 percent of the corporate income tax falls to workers. And some of those workers are executives and other highly paid people. Overall, the budget office estimated that about half of corporate taxes were borne by the top 1 percent of income earners in 2013.
THE COST: Trump's version of the corporate tax cut would lower revenue by about $2.3 trillion*.
Lowering individual tax rates
THE PLAN: Trump has called for three individual tax brackets: The top tax rate would drop from 39.6 percent now to 35 percent, and there would be lower brackets with 25 percent and 10 percent rates.
House Republicans have called for a similar structure of three brackets, with rates of 33 percent, 25 percent, and 12 percent.
WHO BENEFITS: We don't know the income levels that would correspond to each bracket, making it harder to know who would get tax cuts.
Today, however, the top 39.6 bracket kicks in at $470,700 for married couples and $418,400 for individuals.
THE COST: Trump's version of individual rate cuts would lower tax revenue by about $2 trillion.
Increase the standard deduction
THE PLAN: The standard deduction allows families to deduct a set amount of money from their taxable income. Trump has called for doubling it, while House Republicans would significantly increase it.
WHO BENEFITS: Doubling the standard deduction would mean that many people would no longer need to spell out, or itemize, specific deductions to get a tax break. As a result, tens of millions of people would likely have an easier time filling out their taxes and many lower-income households would see their tax liability wiped out altogether.
Nevertheless, it is impossible to say how many or which families would get relief without knowing how the tax plan would change tax brackets and personal exemptions.
THE COST: Trump's version would cost the Treasury about $700 billion over a decade.
Create a special tax rate for sole proprietorships, partnerships and S-corporations
THE PROVISION: Republicans favor creating a new special top tax rate for businesses that file through the individual side of the tax code. The House Republican plan would set that rate at 25 percent, while Trump would make it even with the corporate rate at 15 percent. The joint statement didn't specify where the rate would be.
WHO BENEFITS: The special tax rate would ensure that mom-and-pop businesses get tax cuts with giant C-corporations. But many of the so-called pass-throughs that file through the individual side of the tax code are big businesses, including financial companies such as private equity firms. A significant portion of pass-through income goes to big businesses, and about half flows to the top 1 percent of income earners, according to the Center on Budget and Policy Priorities, a left-of-center think tank.
THE COST: The special tax rate would cut taxes by about $2 trillion. About half the revenue losses would come from the tax cut for existing businesses. The other half reflects that many salary earners would create small business structures such as LLCs to take advantage of the rate.
Eliminate the estate tax
THE PROVISION: Republicans want to eliminate inheritance and gift taxes. Getting rid of the "death tax," as they call it, was not mentioned in the GOP joint statement. Nevertheless, it is likely to remain a goal.
WHO BENEFITS: Under current law, few people face the 40 percent estate tax. For married couples, the tax kicks in for estates of just under $11 million. As a result, only about 11,000 individuals dying in 2017 will see their estates taxed, according to the Tax Policy Center.
THE COST: Over 10 years, doing so would lose about $240 billion.
Eliminate itemized deductions
THE PROVISION: GOP negotiators have called for getting rid of many of the deductions that taxpayers claim by "itemizing" specific deductions, rather than claiming the standard deduction. That include breaks such as the mortgage interest deduction and the deduction for state and local income taxes.
Each of those deductions would be politically difficult to cut. Republicans have not indicated which would be on the table.
WHO PAYS: Different deductions benefit different groups. For instance, the deduction for mortgage interest payments helps homeowners, builders and real estate agents.
But overall, itemized deductions benefit relatively higher earners. Eliminating them altogether would raise taxes on the top half of the income distribution, according to the Congressional Budget Office.
HOW MUCH: Getting rid of all itemized deductions, except for the ones for mortgage interest and charitable giving, would raise about $1.5 trillion. But Republicans are likely not to go that far.
Eliminate business tax breaks
THE PROVISION: The business tax code is filled with breaks for different industries and activities. Republicans have called for getting rid of as many as possible in return for lowering rates.
WHO PAYS: Businesses would pay taxes on more of their income but, in return, they would pay lower rates.
HOW MUCH: About $272 billion of business tax breaks could be axed.
Ending the deductibility of interest payments
THE PROVISION: House Republicans have proposed limiting businesses' ability to deduct interest payments on debt.
WHO PAYS: Companies that rely on lots of debt — that is, borrowing — to undertake projects, such as real estate and energy companies.
HOW MUCH: Getting rid of interest deductibility would net the Treasury about $1 trillion over a decade, the Tax Foundation estimated.
Allow companies to immediately write off the cost of new investments
THE PROVISION: Under the current code, companies can deduct the cost of new investments from their taxable income, but have to do so over a period of years, according to a complicated schedule.
House Republicans have proposed allowing businesses to write off new investments in the first year, a policy known as "full expensing." The joint statement said that the GOP would aim for an "unprecedented" level of first-year write-offs, while stopping short of committing to full expensing.
WHO BENEFITS: Businesses that make big capital expenditures, such as telecom companies, or any business considering new real estate, machinery, or other investment. House Republicans believe that the provision would lead to lots of new business investment, spurring economic growth.
HOW MUCH: Full expensing would be costly, about $880 billion, according to the Tax Foundation.
THE PROVISION: Republicans argue that overhauling the tax code would generate faster economic growth so more revenue would flow into the Treasury because more people would be working and earning more.
In measuring whether their tax legislation lowers federal revenue, they plan on taking into account those new taxes from faster economic growth, a way of estimating tax changes referred to as a "dynamic analysis."
HOW MUCH: Depending on how low rates go, and the other parts of the plan, the dynamic effect could range from zero to $1 trillion, depending on which model Republicans use to gauge it.
Off the table
THE PROVISION: House Republicans proposed changing the corporate tax so that only income from sales in the U.S. is taxable. That would involve border-adjusting corporate taxes, so that exports are not taxed but the cost of imported goods cannot be deducted from taxable income.
However, congressional Republican leadership and the Trump administration said in their joint statement that the idea of adjusting corporate taxes at the border won't be part of their planned tax code overhaul.
WHO PAYS: Who would end up shouldering the border-adjusted corporate tax is a complicated question that would depend on whether and how much the dollar appreciated in response to the rest of the world scrambling to get dollars to buy tax-free U.S. exports.
In the end, however, the tax likely would fall partly on U.S. consumers and partly on foreign companies. Also, companies that are really U.S. companies but have successfully pretended that their income is from tax havens would see that income taxed by the Treasury.
HOW MUCH: Because the U.S. imports more than it exports, border adjustment would raise about $1 trillion if the corporate tax rate were 20 percent in the first decade, according to the Tax Foundation. In future years, though, if the U.S. ran a trade deficit, the Treasury would lose money.
* Unless otherwise noted, figures are from an analysis of a plan like the Trump administration's published by the Tax Policy Center, a nonpartisan, nonprofit think tank currently headed by a former Obama Treasury official.
• This article will be updated regularly.