Standard and Itemized Deductions
Mortgage interest deduction: limits and who can claim it in 2026
Short answer
The mortgage interest deduction lets homeowners who itemize subtract interest on up to $750,000 of debt used to buy, build or substantially improve a main home or one second home ($375,000 if married filing separately). Older loans taken out by December 15, 2017 keep a $1 million limit. For 2026, mortgage insurance premiums are deductible again, subject to an income phaseout.
- 01Loan limit, debt after Dec. 15, 2017
- $750,000 ($375,000 married filing separately)
- 02Loan limit, debt on or before Dec. 15, 2017
- $1,000,000 ($500,000 married filing separately)
- 03Homes that qualify
- Main home plus one second home
- 04Mortgage insurance premiums
- Deductible again from 2026; phases out above $100,000 AGI
- 05Where it goes
- Schedule A (Form 1040)
Can I deduct mortgage interest? Who qualifies
Yes, if you itemize and the loan meets the rules. The mortgage interest deduction is an itemized deduction, so it only helps when your Schedule A total beats your standard deduction ($16,100 single, $32,200 joint for 2026). If you take the standard deduction, the interest you paid gives you no separate tax break.
Beyond itemizing, IRS Publication 936 sets out these conditions:
A qualified home can be a house, condominium, cooperative apartment, mobile home, or even a boat or RV, as long as it has sleeping, cooking and toilet facilities. You can count your main home and one second home. Interest on a third property is personal interest and is not deductible, unless the property is a rental, in which case it belongs on Schedule E, not Schedule A.
Mortgage interest deduction limits in 2026
The limit is on the loan balance, not on the interest. It applies to home acquisition debt, meaning money used to buy, build or substantially improve the home that secures the loan. The 2025 tax law made the post-2017 limits permanent, so they apply to 2026 and later years with no scheduled end date.
| When the debt was taken out | Limit | Married filing separately |
|---|---|---|
| After December 15, 2017 | $750,000 | $375,000 |
| On or before December 15, 2017 | $1,000,000 | $500,000 |
| Binding contract signed before Dec. 15, 2017, closed before April 1, 2018 | $1,000,000 | $500,000 |
The limits cover your main and second home combined. If you have an older loan, its balance counts against the $750,000 limit for any newer debt. A refinance keeps the older date only up to the balance that was refinanced; any cash-out beyond that is new debt.
What happens if your loan is over the limit
You deduct a share of the interest. Publication 936 has a worksheet that uses your average balance for the year. For example, if a mortgage taken out in 2023 averaged $900,000 and you paid $54,000 of interest, the deductible share is $750,000 divided by $900,000, or 83.3%. You would deduct $45,000 and the remaining $9,000 would be nondeductible personal interest.
Is home equity loan interest deductible?
Only when the money went into the home. Interest on a home equity loan or line of credit is deductible if you used the proceeds to buy, build or substantially improve the home that secures it, and the total debt stays within the limits above. Spending the money on a car, tuition, a vacation or paying off credit cards makes that interest nondeductible, no matter when the loan started.
Substantial improvements add value, extend the home's life or adapt it to a new use: a new roof, an addition, a remodeled kitchen. Routine repairs such as repainting do not count. Keep contractor invoices and bank records showing where the loan money went, because the lender's Form 1098 does not report how you spent it.
Form 1098 and what to enter on Schedule A
Your lender sends Form 1098 by early February if you paid $600 or more of interest. Here is what each box means for the interest section of Schedule A:
- Box 1: mortgage interest you paid during the year. This is your starting number.
- Box 2: outstanding principal at the start of the year, which helps you check the $750,000 limit.
- Box 3: the origination date, which tells you whether the $1 million or $750,000 limit applies.
- Box 4: refunds of overpaid interest from an earlier year, which may be income if you deducted it before.
- Box 5: mortgage insurance premiums, deductible for 2026 subject to the phaseout.
- Box 6: points paid on the purchase of a main home.
Points on a purchase loan for your main home are usually deductible in full in the year paid if they meet the tests in Publication 936. Points on a refinance are generally spread over the life of the loan. If you paid interest to a private lender or seller who did not issue a Form 1098, you can still deduct it, but you must give that person's name, address and taxpayer ID on Schedule A.
Is the mortgage interest deduction worth claiming?
Run the numbers with your other items. A single filer who paid $12,000 of mortgage interest and $6,000 of property and state income tax has $18,000 of itemized deductions, beating the $16,100 standard deduction by $1,900. A joint couple with the same numbers would still be $14,200 short of their $32,200 standard deduction and gets no benefit from the interest.
Property tax belongs in the state and local tax total, not the interest section; see the SALT deduction cap for that limit. Our itemize or standard deduction guide walks through the full comparison, and charitable deduction limits covers the other big Schedule A item most homeowners have.
Common questions
What is the mortgage interest deduction limit for 2026?
Interest is deductible on up to $750,000 of home acquisition debt ($375,000 married filing separately) for loans taken out after December 15, 2017. Loans from on or before that date keep a $1,000,000 limit ($500,000 married filing separately).
Is PMI tax deductible in 2026?
Yes. Starting with 2026 returns, qualified mortgage insurance premiums on contracts issued after 2006 are deductible again if you itemize. The deduction phases out between $100,000 and $109,000 of AGI.
Can I deduct mortgage interest if I take the standard deduction?
No. Mortgage interest is only deductible on Schedule A, so you must itemize to claim it.
Can I deduct mortgage interest on a second home?
Yes, for one second home, as long as the combined debt on both homes stays within the $750,000 or $1,000,000 limit. If you rent the second home out part of the year, you must also use it personally enough for it to count as a residence.
Can I deduct mortgage interest if my name is not on the loan?
Generally you must be legally or equitably obligated on the debt and actually pay the interest. Publication 936 covers the cases where someone who is not on the mortgage but owns the home and pays the interest can still deduct it.
Sources
- Publication 936, Home Mortgage Interest Deduction irs.gov
- Publication 505 (2026), Tax Withholding and Estimated Tax irs.gov
- 26 U.S. Code 163(h), qualified residence interest (statute text) law.cornell.edu
- Rev. Proc. 2025-32 (2026 standard deduction) irs.gov
We check figures against these official pages. Rules change; confirm anything that affects a deadline or payment with the agency before you act.
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