Where Does Mortgage Interest Go on 1040: Schedule A, Line 8a

Mortgage interest is reported on Schedule A (Form 1040) in the “Interest You Paid” section, on Lines 8a, 8b, or 8c depending on how the interest was documented. Once you total your itemized deductions on Schedule A, that figure moves to Form 1040, Line 12e, where it reduces your taxable income in place of the standard deduction.¹

Which Schedule A Line to Use

The three lines split the interest by how it was reported to you.

Line 8a: Interest From Form 1098

Line 8a is for the mortgage interest and points your lender reported on Form 1098. If you received more than one Form 1098 during the year — from multiple loans or a refinance — add the amounts and enter the combined total on this line. If your loan balance exceeds the debt limits described below, enter only the deductible portion after running the limitation calculation.²

Line 8b: Interest Not Reported on a 1098

Line 8b is for mortgage interest you paid to someone who did not issue a Form 1098, most often a seller in a seller-financed purchase. Write the recipient’s name, address, and taxpayer identification number on the dotted lines beside Line 8b, and give the recipient your Social Security number in return. Failing to supply this information can result in a $50 penalty.²

Line 8c: Points Not Shown on the 1098

Line 8c captures deductible points that your Form 1098 didn’t include. This most often comes up after a refinance, since lenders typically don’t report those points in Box 6. Points on a refinance are generally deducted ratably over the life of the loan rather than in one year, while points paid to buy your principal residence can usually be deducted in the year paid.³ If you pay off a refinanced mortgage early, any remaining unamortized points come off in that final year.⁴

Start With Form 1098

Your servicer sends Form 1098 (Mortgage Interest Statement) if you paid $600 or more in mortgage interest during the year, and it must arrive by January 31.⁵ Two boxes drive your Schedule A entries:

Box 1 shows the total mortgage interest received during the year. It does not include points, government subsidy payments, or seller-paid buydown amounts.⁶
Box 6 shows points paid on the purchase of your principal residence that the lender is required to report. Other deductible points may not appear here.⁶

Confirm that your Social Security number and outstanding balance on the form match your records before you copy anything over. Mismatches trigger automated IRS notices. Keep the 1098 and supporting records for at least three years after filing.⁷

From Schedule A to Form 1040

After you fill in Lines 8a, 8b, and 8c, Schedule A totals your mortgage interest alongside your other itemized deductions: medical expenses, state and local taxes, charitable contributions, and casualty losses. The combined total lands on Schedule A, Line 17, and you carry that number to Form 1040, Line 12e.¹ That amount replaces the standard deduction on your return.

Itemize Only If It Beats the Standard Deduction

Putting mortgage interest on Schedule A saves you nothing unless your itemized deductions together exceed the standard deduction for your filing status. For tax year 2026, the standard deduction is $16,100 for single filers or married filing separately, $32,200 for married filing jointly, and $24,150 for heads of household.⁸

Add your mortgage interest to your state and local taxes (capped for most filers), charitable contributions, and qualifying medical expenses. If the sum is larger than your standard deduction, itemize. Otherwise, take the standard deduction and skip Schedule A.

What Actually Qualifies on Line 8a

Federal law treats personal interest as non-deductible but carves out “qualified residence interest” — interest on a loan secured by your home that was used to buy, build, or substantially improve the property.⁹ A qualified residence is your main home plus one second home you select for the year. Unsecured loans used to buy a house don’t qualify even if every dollar went into the property.

How much interest you can deduct depends on when the loan closed:

For loans taken out after December 15, 2017, interest is deductible on the first $750,000 of mortgage debt ($375,000 if married filing separately). The One, Big, Beautiful Bill Act of 2025 made this limit permanent.
For loans taken out before December 16, 2017, the earlier $1,000,000 limit ($500,000 if married filing separately) still applies to that debt.¹⁰

When your total balance exceeds the applicable limit, calculate the deductible share by dividing the limit by the total balance and multiplying by the interest paid, then enter only that portion on Line 8a.¹⁰

Refinances

A refinance is treated as acquisition debt up to the balance of the old mortgage just before the refinance. Any cash-out amount above that balance qualifies only if you spent it to buy, build, or substantially improve the home. The date of the original loan controls which debt limit applies, so refinancing a pre-2018 mortgage doesn’t drop you to the $750,000 cap as long as the new loan doesn’t exceed the old balance.¹⁰

Home Equity Loans and HELOCs

Interest on a home equity loan or HELOC is deductible only when you used the proceeds to buy, build, or substantially improve the home securing the loan. If you used a HELOC to pay off credit cards, fund a vacation, or cover other personal expenses, the interest does not go on Schedule A. When the proceeds do qualify, the debt counts toward the same combined $750,000 or $1,000,000 cap.¹⁰

Second Home You Rent Out

If you rent your second home for fewer than 15 days during the year, report the full mortgage interest on Schedule A as you would for any personal residence, and don’t report the rental income at all. Once rental use reaches 15 days or more, split the mortgage interest between personal use (Schedule A) and rental use (Schedule E).¹¹

Mortgage Insurance Premiums

For tax year 2026, premiums for private mortgage insurance (PMI) or FHA mortgage insurance (MIP) tied to a loan used to buy your home are treated as deductible mortgage interest and count against the same $750,000 combined debt limit. The deduction phases out once adjusted gross income exceeds $100,000 ($50,000 if married filing separately), reducing by 10 percent for each $1,000 over that threshold.⁹

Late Fees and Prepayment Penalties

Two mortgage costs are easy to miss on Schedule A. A late payment charge on a mortgage payment is deductible as mortgage interest, provided the fee wasn’t for a specific service the lender performed. A prepayment penalty for paying the loan off early is also deductible as mortgage interest under the same condition.¹⁰ Both go into the interest total you enter on Line 8a or 8b, depending on how they were reported.

Amending a Return If You Already Took the Standard Deduction

If you filed and claimed the standard deduction only to realize your mortgage interest and other deductions would have beaten it, file Form 1040-X to switch to itemizing. You generally have three years from the date the original return was filed, or two years from the date the tax was paid, whichever is later. Returns filed before the April due date are treated as filed on the due date for this deadline.¹²

1
Internal Revenue Service. Schedule A (Form 1040)
2
Internal Revenue Service. Instructions for Schedule A (Form 1040) – Itemized Deductions
3
Internal Revenue Service. Topic No. 504, Home Mortgage Points
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Internal Revenue Service. Instructions for Schedule A (Form 1040)
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Office of the Law Revision Counsel. 26 U.S. Code 6050H – Returns Relating to Mortgage Interest Received in Trade or Business From Individuals
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Internal Revenue Service. Form 1098 Mortgage Interest Statement
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Internal Revenue Service. How Long Should I Keep Records?
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Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments From the One, Big, Beautiful Bill
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Office of the Law Revision Counsel. 26 U.S. Code 163 – Interest
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Internal Revenue Service. Publication 936, Home Mortgage Interest Deduction
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Internal Revenue Service. Publication 527, Residential Rental Property
12
Internal Revenue Service. Instructions for Form 1040-X