Last reviewed: 3 October 2026

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The mortgage interest deduction, explained

The IRS lets some homeowners deduct mortgage interest on their tax return. This page repeats what the IRS’s own publication says about the conditions and limits, and who to ask about your own taxes.

What this term means: Itemizing means listing deductible expenses on Schedule A instead of taking a standard amount (our plain-language gloss). The IRS says a secured debt is one in which you sign an instrument, such as a mortgage or deed of trust, that makes your ownership in a qualified home security for payment of the debt, provides that in case of default your home could satisfy the debt, and is recorded or otherwise perfected under any state or local law that applies.^[1]

The conditions the IRS lists

The IRS defines home mortgage interest generally as any interest you pay on a loan secured by your main home or a second home, and says the loan may be a mortgage to buy your home or a second mortgage.^[1]

• You file Form 1040 or 1040-SR and itemize deductions on Schedule A (Form 1040).^[1]
• The mortgage is a secured debt on a qualified home in which you have an ownership interest.^[1]
• Both you and the lender must intend that the loan be repaid.^[1]

When all the interest is deductible, per the publication

The IRS says you can deduct all of your home mortgage interest if all your mortgages fit into one or more of three categories at all times during the year.^[1]

The dollar limits for the second and third categories apply to the combined mortgages on your main home and second home.^[1] If a mortgage does not fit any category, the IRS says to use Part II of the publication to figure the interest you can deduct.^[1] The publication includes a figure (Figure A) for checking whether your home mortgage interest is fully deductible.^[1]

There is a binding-contract exception: a taxpayer who entered into a written binding contract before December 15, 2017 to close on the purchase of a principal residence before January 1, 2018, and who purchased the residence before April 1, 2018, is treated as having incurred the debt before December 16, 2017.^[1]

Home equity loans and other changes the IRS flags

• Interest on home equity loans and lines of credit is deductible only if the borrowed funds are used to buy, build or substantially improve the home that secures the loan, and the loan must meet other requirements.^[1]
• No matter when the debt was incurred, you can no longer deduct interest from a loan secured by your home to the extent the proceeds were not used to buy, build or substantially improve your home.^[1]
• The 2025 edition says the itemized deduction for mortgage insurance premiums has expired and you can no longer claim it.^[1] That statement is about 2025 returns.
• Later law changes this for 2026. Public Law 119-21 (signed 4 July 2025), section 70108, amends 26 U.S.C. 163(h)(3)(F) to add a rule that clause (iv) of subparagraph (E), the clause that ended the treatment of mortgage insurance premiums as qualified residence interest for amounts paid or accrued after December 31, 2021, “shall not apply,” and says its amendments apply to taxable years beginning after December 31, 2025.^[2] The IRS’s 2026 draft Schedule A (Form 1040), which it marks “not for filing,” has a line 8d, “Mortgage insurance premiums (see instructions),” where the final 2025 form says “Reserved for future use.”^[3] We have not found IRS instructions for 2026 that explain the conditions or limits, so this page does not state them. Check the current-year IRS instructions before you rely on this.

The publication also covers points, Form 1098 and other topics listed in its table of contents. This page does not summarize them. See our guides to HECM, HELOC and home equity loans and how a refinance works for the loan side.

Who benefits?

The IRS publication does not say how many people benefit or whether the deduction lowers any particular person’s tax. It states the conditions above. Whether itemizing applies to you, and what the deduction is worth, depends on your whole tax return, so it is a question for a tax professional.

How to verify this yourself

Open IRS Publication 936 for the tax year you are filing. The IRS says to check its Publication 936 page for later developments, such as legislation enacted after publication, and points to its Interactive Tax Assistant for tax questions it does not answer. Your lender’s Form 1098, if you receive one, reports interest paid; the publication’s table of contents lists a section on it. Our published standard and the Register cover how we check loan originators, not tax treatment.

What this page does not cover

This page is general information, not tax or legal advice, and it is not a substitute for the IRS publication. It does not apply the rules to anyone’s facts, estimate a deduction, or say whether to itemize. The debt figures are those in the 2025 edition for 2025 returns and can change; the 2026 mortgage insurance premium point rests on the statute and the draft form, not on a final IRS publication for 2026. It does not cover points, mortgage credit certificates, rental use, home offices or business use. Ask a qualified tax professional or the IRS about your own return. This page was last reviewed 3 October 2026.

Your next step

Before you rely on a figure, open the IRS publication for your filing year and, for your own return, ask a tax professional. Then return to the Mortgage help library.