What is a qualified home for mortgage interest?

Two things a qualified home needs

Publication 936 sets two conditions for any home mortgage interest deduction, and a qualified home is at the center of both. You must file Form 1040 or 1040-SR and itemize on Schedule A, and the mortgage must be a secured debt on a qualified home in which you have an ownership interest. The publication adds that both you and the lender must intend that the loan be repaid. If the property is not a qualified home, the interest on a loan secured by it may still be deductible if the proceeds were used for business, investment or other deductible purposes, and is otherwise personal interest, which is not deductible.

What can be a home

The publication’s definition is a list rather than a test: a house, condominium, cooperative, mobile home, house trailer, boat or similar property that has sleeping, cooking and toilet facilities. A boat with a galley, berth and head can therefore be a home. A pop-up camper with no toilet would not fit the wording. The facilities, not the label, decide.

Main home and second home

You can have only one main home at any one time: the home where you ordinarily live most of the time. A second home is one that you choose to treat as such. If you do not hold it out for rent or resale during the year, it qualifies with no use requirement. If you rent it out, you must use it more than 14 days or more than 10% of the days rented at a fair rental, whichever is longer. The calculator above applies that test. Only one second home counts in a year. The second home page covers choosing between several.

Divided use

The only part of your home that is a qualified home is the part you use for residential living. If you use part for something else, such as a home office, you must allocate: divide both the cost and the fair market value between the qualified part and the rest. The split can reduce your home acquisition debt, which is capped at the cost of the home plus improvements. See the home office interest page.

Renting out part of your home

You may treat the rented part as used by you for residential living only if three things are true: the tenant uses it primarily for residential living, it is not a self-contained residential unit with separate sleeping, cooking and toilet facilities, and you do not rent the same or different parts to more than two tenants at any time in the year. Two people who share sleeping quarters, and their dependents, count as one tenant. A basement apartment with its own kitchen and bath fails the second condition.

Homes under construction, destroyed or in a time-share

A home under construction can be treated as qualified for up to 24 months, but only if it becomes your qualified home when it is ready for occupancy; the 24 months can start any time on or after construction begins. A home destroyed by fire, storm, tornado, earthquake or other casualty can continue to be treated as qualified if, within a reasonable time, you rebuild and move in or sell the land. A time-share qualifies if it meets all the requirements, and if you rent it out it counts as a second home only if you also use it as a home, counting days only during the time you have a right to use it or receive benefits from renting it.

Married taxpayers

If you are married and file jointly, your qualified homes can be owned jointly or by one spouse. On separate returns where you own more than one home, each spouse can take into account only one home unless both consent in writing, in which case one spouse can take both the main home and a second home.

Secured debt, briefly

A debt is secured if you sign an instrument such as a mortgage, deed of trust or land contract that makes your ownership in the qualified home security for the debt, provides that the home could satisfy the debt on default, and is recorded or otherwise perfected under state or local law. The publication’s wraparound example shows the failure mode: a seller who did not record or perfect a $90,000 wraparound note under state law left the buyer unable to deduct that interest. A lien that attaches without your consent, such as a mechanic’s lien or judgment lien, does not make a debt secured by your home.

Cooperatives

Stock in a cooperative housing corporation can be a qualified home if you are a tenant-stockholder entitled to live in the unit because you own the stock. The co-op page covers that case. For limits and the next step, see the acquisition debt page and the mortgage interest deduction calculator.

Sources

• IRS Publication 936, Home Mortgage Interest Deduction (2025): “Qualified Home” and “Secured Debt”, plus the Reminders, Table 1 and Table 2. Read November 2, 2026.

Edition read: Publication 936 (2025), for use in preparing 2025 returns. Dollar limits in this publication are for 2025; the publication notes that tax legislation enacted July 4, 2025 (P.L. 119-21) may affect federal deductions, so check IRS.gov/Pub936 and the Schedule A instructions for your tax year. This page summarizes the publication and does not replace it. Marked for human review.