The Benefits of the State and Local Tax Deduction by County

The House of Representatives passed a bill last week that would make permanent the individual provisions of the Tax Cuts and Jobs Act (TCJA). One such provision is the $10,000 cap on the state and local tax (SALT) deduction. This map shows the variation, by county, in the amount of that deduction taken by taxpayers. As you can see, the benefits of the SALT deduction vary widely by county: the average deduction across the ten counties with the highest SALT deduction is $15,736, compared to an average of $1,727 for the country overall.

The measurement used here is mean deduction amount taken per return—in other words, the total value of all the deductions for state and local taxes, divided by the number of returns filed.

This map is interactive—hover the mouse over a given county to see its average amount of state and local deduction claimed.

Two factors drive this regional variation. The first is taxpayer income. High-income taxpayers are more likely to itemize, while low-income taxpayers are more likely to take the standard deduction. In 2016, 93.1 percent of taxpayers with adjusted gross incomes (AGIs) of $500,000 or more itemized, compared to only 19.1 percent of taxpayers with AGIs between $25,000 and $49,999. This variation causes the SALT deduction to be most valuable in high-income counties. The number of itemizers is projected to decline in 2018 as a result of the TCJA, but the SALT deduction will continue to benefit those wealthier taxpayers who itemize.

The second factor driving the regional variation in SALT deductions is variation in state and local tax burdens across the country. The greatest beneficiaries of the SALT deduction generally have high state and local taxes. The ten counties benefiting most from the deduction are located in just four states, all with high-tax burdens: New Jersey, California, New York, and Connecticut.

As it happens, these four states come in dead last in the Tax Foundation’s 2019 State Business Tax Climate Index, released last week.

Prior to the TCJA, the value of the SALT deduction was effectively unlimited, but the new cap limits the deduction to $10,000 per household. If Congress does not make permanent the individual tax provisions, the SALT cap will expire as scheduled after 2025.