Quick Answer
You can deduct mortgage interest on up to $750,000 in acquisition debt for homes purchased after December 15, 2017. For older mortgages, the limit is $1 million. The average homeowner deducts $12,000-$18,000 annually in mortgage interest, saving $2,600-$4,300 in federal taxes depending on their tax bracket.
Best Answer
Robert Kim, Tax Return Analyst
Best for homeowners who want to understand current mortgage interest deduction rules and limits
Current mortgage interest deduction limits
The mortgage interest deduction underwent significant changes with the Tax Cuts and Jobs Act of 2017. The rules depend on when you purchased your home and how much debt you carry.
For homes purchased after December 15, 2017, you can deduct interest on up to $750,000 in acquisition debt ($375,000 if married filing separately). For homes purchased before this date, the higher $1 million limit still applies.
Example: $800,000 home purchased in 2023
Loan details:
Deductible amount: Since the mortgage ($640,000) is under the $750,000 limit, the full $44,800 in interest is deductible.
Tax savings: In the 24% bracket, this saves $10,752 in federal taxes alone.
Understanding acquisition debt vs. home equity debt
Acquisition debt: Money borrowed to buy, build, or substantially improve your home. Interest is deductible up to the limits.
Home equity debt: Money borrowed against home equity for other purposes (cars, college, etc.). Interest is NOT deductible unless used for home improvements.
Mortgage interest deduction by loan amount
*Limited to interest on first $750,000 of debt
What counts as mortgage interest
Fully deductible:
Not deductible:
Special situations and calculations
Multiple properties
You can deduct interest on a primary residence plus one second home, but the combined debt cannot exceed $750,000.
Refinancing
Points paid on a refinance must be amortized over the life of the loan unless you use cash to pay them.
Construction loans
Interest during construction is generally deductible once you move in and the loan converts to a permanent mortgage.
Key factors that affect your deduction
What you should do
1. Track your Form 1098 from your lender showing interest paid
2. Separate acquisition debt from home equity debt for proper reporting
3. Keep records of home improvements financed with home equity loans
4. Consider timing of refinances to optimize point deductions
5. Consult a professional for complex situations involving multiple properties
[Use our refund estimator](refund-estimator) to see how much your mortgage interest deduction could increase your refund.
Key takeaway: Most homeowners can deduct their full mortgage interest payment, with the average deduction ranging from $12,000-$18,000 annually, saving $2,600-$4,300 in federal taxes depending on income and loan size.
*Sources: [IRS Publication 936](https://www.irs.gov/pub/irs-pdf/p936.pdf), [Tax Cuts and Jobs Act](https://www.congress.gov/bill/115th-congress/house-bill/1)*
Key Takeaway: Most homeowners can deduct their full mortgage interest payment, with the average deduction saving $2,600-$4,300 in federal taxes annually.
Mortgage interest deduction by loan amount
| Mortgage Balance | Annual Interest (7%) | Deductible Interest | Tax Savings (24% bracket) |
|---|---|---|---|
| $400,000 | $28,000 | $28,000 | $6,720 |
| $600,000 | $42,000 | $42,000 | $10,080 |
| $750,000 | $52,500 | $52,500 | $12,600 |
| $900,000 | $63,000 | $52,500* | $12,600 |
More Perspectives
Robert Kim, Tax Return Analyst
Perfect for new homeowners trying to understand how mortgage interest deductions work
Mortgage interest deduction basics for new homeowners
As a first-time homeowner, the mortgage interest deduction will likely become your largest tax deduction. Understanding how it works can help you plan better and maximize your tax savings.
The simple rule
If you bought your home after December 15, 2017, you can deduct interest on up to $750,000 in mortgage debt. For most first-time buyers, this covers your entire mortgage.
First-time buyer example
Your situation: Bought a $375,000 home in 2026
What you can deduct: The full $19,500 in interest (well under the $750,000 debt limit)
Tax savings: If you're in the 22% tax bracket, this deduction saves you $4,290 in federal taxes.
What you'll receive from your lender
Each January, your mortgage company sends Form 1098 showing:
This form has all the information you need for your tax return.
First-year considerations
Points paid: If you paid points to reduce your interest rate, these are fully deductible in the year of purchase. One point equals 1% of your loan amount.
Partial year: If you closed mid-year, you only deduct interest actually paid. Your lender's 1098 form will show the correct amount.
Itemizing vs. standard deduction: You need total itemized deductions exceeding $30,000 (married) or $15,000 (single) to benefit. Mortgage interest alone often makes itemizing worthwhile.
Don't worry about these limits (for most first-time buyers)
The $750,000 debt limit mainly affects luxury home buyers. According to the National Association of Realtors, the median first-time buyer home price is $295,000, well below levels where limits matter.
Key takeaway: First-time homebuyers can typically deduct 100% of their mortgage interest, creating $15,000-$25,000 in deductions and saving $1,800-$6,000 in federal taxes their first year.
Key Takeaway: First-time homebuyers can typically deduct 100% of their mortgage interest, saving $1,800-$6,000 in federal taxes their first year.
Robert Kim, Tax Return Analyst
Designed for homeowners who work from home and need to understand how home office use affects mortgage interest deductions
Mortgage interest with home office considerations
When you claim a home office deduction, it affects how you deduct mortgage interest. You can't "double-dip" by claiming the same expense both as mortgage interest and as part of your home office deduction.
How the split works
If you use the actual expense method for your home office, a portion of your mortgage interest gets claimed as a business expense rather than an itemized deduction.
Example scenario:
Result:
Simplified method advantage
If you use the simplified home office method ($5 per square foot), you keep 100% of your mortgage interest as an itemized deduction. This is often more beneficial.
Comparison for 200 sq ft office:
Simplified method:
Actual expense method (10% office):
The difference is usually small, making the simplified method attractive for its ease.
Tax bracket considerations
Since home office deductions reduce business income (subject to self-employment tax), while mortgage interest reduces regular income, the tax savings can differ:
This makes the actual expense method more valuable for high-earning self-employed individuals.
What you should do
Calculate both methods annually to see which provides better overall tax savings. The best choice depends on your income level, tax bracket, and home office size.
Key takeaway: Homeowners with home offices should compare the simplified vs. actual expense methods annually, as the optimal choice for mortgage interest deduction depends on office size, income level, and overall tax situation.
Key Takeaway: Homeowners with home offices should compare simplified vs. actual expense methods annually to optimize their combined mortgage interest and home office deductions.
Sources
- IRS Publication 936 — Home Mortgage Interest Deduction
- Tax Cuts and Jobs Act — Tax reform legislation that changed mortgage interest limits
Related Questions
Reviewed by Robert Kim, Tax Return Analyst on February 28, 2026
This content is for educational purposes only and is not a substitute for professional tax advice. Consult a qualified tax professional for advice specific to your situation.