Here’s How Congress Might Change Your Taxes

President Trump has promised to make tax reform a priority when Congress returns in September. But beyond a few calls for simplifying the tax code and reducing the corporate tax rate, neither the White House nor Republican leaders on Capitol Hill have said exactly what that plan might look like.

A major sticking point is how to pay for the cuts. Republicans in the Senate intend to approve tax reform with a simple majority without Democratic help under an expedited process called “reconciliation.” Bills passed under this process cannot increase the deficit after ten years—meaning Congress needs a way to balance out the revenue lost by enacting these cuts.

Some ideas that have been discussed in Washington, both openly and quietly, include targeting some popular tax deductions.

Here’s a look at four ways Congress might change your taxes.

Taxing 401(k)s upfront

Earlier this month, Politico reported that an idea “being quietly discussed” was a tax on 401(k) contributions. Americans use these plans to save for retirement, encouraged to do so in part because contributions to them are tax-deductible: the money placed in a 401(k) is currently only taxed when it is taken from the plan, not when it is contributed. Under this revision, you’d be taxed on your retirement savings up front.

How much it would raise: More than $144 billion in revenue over ten years, according to government research from 2014.

Who would be affected: The estimated 55 million American workers who contribute to 401(k) plans.

Who would be opposed: The Americans who use these plans, presumably, as well as the financial services companies who profit from managing these accounts. Financial advisors who want Americans to save for retirement worry this would dissuade them from doing so.

Lowering the cap on mortgage interest deductions

Currently, if you own a home and are paying interest on a mortgage, you’re entitled to a tax deduction on that interest, capped at $1 million. It’s a policy that nominally encourages home ownership, but it disproportionately benefits wealthy Americans, as Dan Kopf at Quartz explained earlier this week. The Trump Administration has considered lowering the cap to $500,000.

How much it would raise: $319 billion over the next decade, according to a study by the Tax Foundation, a tax policy nonprofit group.

Who would be affected: Americans who own homes and claim this deduction—34.1 million people in 2013, according to Forbes.

Who would be opposed: The powerful real estate lobby, which spends more than the pharmaceutical and gun lobbies—$64.8 million in 2016, according to a recent New York Times story on homeownership and wealth inequality. They argue that capping this deduction further would discourage home ownership.

Eliminating the deduction for state and local taxes

Since the government began a federal income tax in 1913, taxpayers have had the option to deduct the amount they pay in state and local taxes from the sum that’s taxed at the national level. This amounts to $96 billion in lost federal tax revenue annually, according to the Tax Policy Center. A bare-bones proposal offered by Trump in April called for getting rid of this deduction.

How much it would raise: Experts estimate that if the state and local tax deduction remains in place, it will cost the government $1.3 trillion in revenue between now and 2026.

Who would be affected: Many Americans, particularly wealthier ones. About one-third of U.S. taxpayers itemize deductions on their federal income tax returns, according to the Tax Policy Center, and the majority of them make more than $100,000 a year. They’re largely concentrated in states with high income taxes: namely California, New York, and New Jersey.

Who would be opposed: State and local governments, who issued a comprehensive report in July delineating the economic impact of eliminating the deduction. The most vocal critics will be in the states mentioned above, which tend to lean Democratic.

Limiting the corporate interest deduction

Republicans have called for eliminating or reducing the corporate tax deduction—a policy that, similar to the mortgage interest deduction, allows companies in debt to avoid paying taxes on the interest on that debt. CNBC calls it the “biggest single corporate pay-for” in the tax proposal submitted by Republicans last year.

How much it would raise: $1.2 trillion over ten years, by some estimates.

Who would be affected: American industries that depend on debt, like real estate, auto manufacturing, and airlines.

Who would be opposed: As CNBC reports, a new coalition of representatives from the telecom, finance, and real estate industries is arguing that eliminating the deduction will be hazardous to American business. “The conclusion is that ultimately it will end up reducing the amount of supply that we can add,” Bob DeWitt, a housing developer in Boston and a member of the coalition, said in remarks. “It will increase the costs of doing business.”