The mortgage interest deduction remains one of the most valuable tax benefits available to homeowners. Whether you’re preparing your 2025 return or planning ahead for 2026, understanding how this deduction works can significantly reduce your taxable income. With recent tax law changes including higher SALT deduction limits beginning in 2026 homeowners have more opportunities than ever to optimize their tax strategy. This guide breaks down the rules, limits, and strategies you need to know to claim the mortgage interest deduction effectively.
What Is the Mortgage Interest Deduction?
The mortgage interest deduction allows homeowners to deduct the interest paid on qualifying home loans, reducing their taxable income. According to IRS Publication 936, you can deduct interest on the first $750,000 of acquisition indebtedness for mortgages taken out after December 15, 2017. Higher limits of up to $1 million apply if your mortgage was originated before that date.
This deduction is available only if you itemize your deductions. For many homeowners especially those with larger mortgages or high property taxes itemizing can provide substantial tax savings.
2026 Mortgage Interest Deduction Limits
Beginning in 2026, the mortgage interest deduction rules remain largely the same, but the overall tax landscape becomes more favorable for homeowners due to changes in the SALT deduction cap.
Deduction Limits by Mortgage Origination Date
These limits apply to the combined total of all qualifying mortgages across your primary and secondary residences.
What Counts as Acquisition Debt?
Only interest on “acquisition indebtedness” is deductible. This includes loans used to:
- Buy a home
- Build a home
- Substantially improve a home
Home equity loan interest is deductible only if the funds were used for home improvements not for personal expenses or debt consolidation.
Major 2026 Change: SALT Deduction Cap Increases
One of the biggest tax changes benefiting homeowners in 2026 is the increase in the SALT (State and Local Tax) deduction cap. Under the One Big Beautiful Bill Act (OBBBA), the SALT cap increases from $10,000 to:
- $40,000 for married filing jointly
- $20,000 for single filers
This expanded cap applies from 2026 through 2029.
Because property taxes and state income taxes are often significant, this change makes itemizing far more advantageous for many homeowners—especially when combined with mortgage interest.
What Loans Qualify for the Mortgage Interest Deduction?
To claim the deduction, your loan must meet the following criteria:
1. Secured by Your Home
The mortgage must be secured by your primary residence or a second home.
2. Used for a Qualifying Purpose
The loan must be used to buy, build, or improve the home securing the loan.
3. Within IRS Debt Limits
Your total acquisition debt must fall within the $750,000 or $1 million limits, depending on when the mortgage originated.
4. You Must Itemize
If your itemized deductions do not exceed the standard deduction, you won’t benefit from claiming mortgage interest.
Example: How Much Can You Save?
Consider a married couple in 2026 with:
- A $600,000 mortgage at 6.5%
- $15,000 in property taxes
- $5,000 in state income tax
Their annual mortgage interest is approximately $39,000, all deductible because it falls under the $750,000 limit. Their SALT total is $20,000, fully deductible under the new $40,000 cap. Combined, their itemized deductions total $59,000, far exceeding the estimated $31,000 standard deduction for married couples in 2026. This results in thousands of dollars in tax savings.
How to Claim the Mortgage Interest Deduction
1. Gather Form 1098
Your lender will send Form 1098 showing the total mortgage interest you paid during the year.
2. Itemize Using Schedule A
Report your mortgage interest, property taxes, and other itemized deductions on Schedule A.
3. Apply IRS Limits
If your mortgage exceeds the allowable debt limit, you must calculate the deductible portion using the IRS worksheet in Publication 936.
4. Include Points (If Applicable)
Points paid to obtain a mortgage may also be deductible under certain conditions.
Tips to Maximize Your Mortgage Interest Deduction
Refinance Strategically
If you refinance a grandfathered mortgage (pre‑2017), you can keep the $1 million limit as long as you don’t increase the principal.
Track Home Improvement Expenses
If you use a home equity loan for improvements, keep detailed records to substantiate the deduction.
Combine With SALT Benefits
The higher SALT cap in 2026 makes itemizing more attractive—especially for homeowners in high‑tax states.
Consider Timing
If you’re close to the standard deduction threshold, timing your mortgage payments or property tax payments may help you exceed it.
Final Thoughts
The mortgage interest deduction remains a powerful tax benefit for homeowners, and upcoming changes in 2026 make it even more valuable. By understanding the rules, limits, and strategies outlined above, you can maximize your tax savings and make homeownership more affordable. Whether you’re planning a home purchase, refinancing, or preparing your next return, staying informed ensures you get the full benefit of this important deduction.
This article provides information only and should not be construed as advice. It is provided without warranty of any kind.