Massachusetts SALT Deduction Calculator 2026

Massachusetts has a unique tax structure among high-tax states: a flat 5% income tax rate that applies to nearly all income. While this is simpler than the progressive systems in neighboring states, when combined with Massachusetts' high property taxes, many residents still exceeded the old $10,000 SALT cap.

Massachusetts' Flat Income Tax

Massachusetts is one of the few states with a flat income tax rate of 5% (with a 4% surtax on income over $1 million, bringing the top rate to 9%). The flat rate makes it simple to estimate your state income tax: on $160,000 of gross income, after standard deductions of approximately $50,000, a typical couple would pay roughly $5,500 in state income tax. This simplicity makes Massachusetts one of the most predictable states for tax planning.

Property Taxes Vary Widely by Municipality

Massachusetts property taxes are set by individual cities and towns, and rates vary dramatically. The average effective property tax rate is approximately 1.15%, but this can range from under 0.5% in some Berkshire County towns to over 2% in communities like Springfield, Brockton, and Lawrence. In the Greater Boston area, where median home values exceed $600,000, annual property tax bills of $6,000 to $10,000+ are common. Towns like Newton, Wellesley, and Lexington routinely see property tax bills exceeding $10,000.

Worked Example: MA Couple Earning $160,000

Consider a married couple living in Massachusetts earning $160,000 combined:

• MA State Income Tax: ~$5,500 (5% flat on ~$110K after deductions)
• Property Tax: ~$7,500
• Total SALT: $13,000

Under the old $10,000 cap, they could only deduct $10,000 of their $13,000 in SALT payments. Under the new $40,400 cap, they can deduct the full $13,000. That's an additional $3,000 in deductions. At the 22% federal tax bracket, this translates to approximately $660 in annual tax savings.

Why Massachusetts Residents Benefit from the SALT Increase

While Massachusetts' flat 5% income tax rate is moderate compared to states like New York and California, the combination with high property taxes -- especially in the Greater Boston metro area -- means many Massachusetts homeowners exceed the old $10,000 SALT cap. The increased cap to $40,400 ensures that nearly all Massachusetts taxpayers can now fully deduct their combined state income and property taxes. The benefit is most pronounced for homeowners in high-cost suburban communities where property taxes are the largest component of SALT.

Source: Massachusetts Department of Revenue