As Congress edges closer to key tax deadlines, a familiar fight is back on the agenda: whether to lift or extend the limit on state and local tax deductions, known as SALT. The cap, introduced in 2018, reshaped tax bills for millions in high-tax states and remains one of the most contested elements of recent tax law.
The current $10,000 limit affects taxpayers who itemize deductions on their federal returns. Lawmakers from both parties are weighing changes ahead of a 2025 expiration, when many provisions of the 2017 tax law are set to lapse. The stakes are significant for households in states such as New York, New Jersey, California, and Illinois.
How the SALT Cap Changed Filing
Before the cap, taxpayers who itemized could deduct the full amount of state and local income and property taxes. That changed with the 2017 Tax Cuts and Jobs Act, which set a $10,000 ceiling starting in the 2018 tax year. The law also nearly doubled the standard deduction, reducing the number of people who itemize each year.
“Before 2018, the tax break — including state and local income and property taxes — was unlimited for filers who itemized deductions.”
The shift cut the share of itemizers from nearly one in three filers to about one in ten, according to tax policy estimates. Many middle- and upper-income homeowners in high-tax regions saw larger federal tax bills, even as overall federal rates fell for many households.
Who Pays More Under the Cap
The impact has been uneven. Households with higher incomes and property values in states with steep tax burdens were most affected. Mortgage interest, charitable gifts, and SALT once combined to make itemizing attractive for many. With the cap in place, fewer filers cross the threshold where itemizing beats the standard deduction.
Supporters of the cap argue that the prior system functioned as a federal subsidy for high-spending states. They say limiting the deduction helps broaden the federal tax base and helped finance rate cuts in 2017. Opponents counter that the cap leads to double taxation by taxing income that was already taxed at the state and local level. They say it pressures state budgets and can discourage homeownership in certain markets.
Political Fight Rekindles
Members of Congress from high-tax states, including Democrats and some Republicans, have pressed to raise or eliminate the cap. Proposals have included lifting the ceiling for middle-income households while keeping limits for high earners, or raising the cap for married couples who file jointly.
Fiscal hawks warn that a rollback could cost hundreds of billions over a decade, depending on the scope, and would favor higher earners. Some lawmakers have floated temporary relief or geographic adjustments, but those options add complexity to the code.
- Current cap: $10,000 for most filers
- Married filing separately: $5,000 cap
- Key date: Major provisions expire after 2025
State Workarounds and IRS Pushback
After 2018, several states tried to blunt the cap with creative policies. Some created charitable funds that allowed taxpayers to reclassify tax payments as charitable contributions. Others set up pass-through entity taxes so business owners could deduct state taxes at the entity level, bypassing the individual cap.
The IRS moved quickly against the charitable credit strategy, limiting its effectiveness. However, the pass-through entity tax approach remains in use in many states, with federal guidance allowing it in certain cases. These steps reduced the cap’s bite for some business owners but left wage earners with fewer options.
What the Data Suggests
Analysts say the SALT cap shifted benefits up and down the income scale in complex ways. Many moderate earners now take the larger standard deduction instead of itemizing, simplifying their returns and sometimes lowering taxes. High earners who still itemize often face the cap directly.
Housing markets in high-tax suburbs have absorbed part of the hit. Real estate agents report that buyers factor in after-tax carrying costs more carefully since 2018, especially for properties with high property taxes. The effect varies by region and has been overshadowed at times by mortgage rate swings and inventory shortages.
What Comes Next
With the 2025 sunset approaching, Congress must decide whether to extend the cap, modify it, or allow it to expire along with other individual tax provisions. Any change will need to balance fiscal costs, regional equity, and the political reality of a closely divided legislature.
For households, the key questions are whether itemizing makes sense and how state taxes factor into total costs. Tax advisers say filers should review projections for 2024 and 2025 and watch for late-year changes that could affect estimated payments and withholding.
The bottom line: the debate over SALT is no longer just about one line on a tax return. It sits at the center of a broader fight over who benefits from federal tax policy and how Washington should treat high-tax states. If Congress cannot reach a deal, the cap’s fate will be decided by the clock, setting up a year of intense negotiations and high stakes for taxpayers.
