Quick Answer
The mortgage interest deduction limit is $750,000 in mortgage debt for married filing jointly ($375,000 for married filing separately). This applies to mortgages taken after December 15, 2017. Mortgages from before that date are grandfathered at the old $1 million limit until refinanced or the home is sold.
Best Answer
Michelle Woodard, Tax Policy Analyst
Best for homeowners who got their mortgage before December 15, 2017
Current mortgage interest deduction limits for 2026
The mortgage interest deduction limit depends on when you got your mortgage and your filing status:
The Tax Cuts and Jobs Act of 2017 reduced the limit for new mortgages, but existing mortgages were grandfathered under the old, higher limit.
How grandfathering works for pre-2018 mortgages
If you got your mortgage before December 16, 2017, you can deduct interest on up to $1 million in mortgage debt until you:
1. Refinance the mortgage (new limit applies to the refinanced amount)
2. Sell the home (any new mortgage gets the $750,000 limit)
3. Take out additional mortgage debt (new debt gets the lower limit)
Example: Grandfathered vs. new mortgage limits
Scenario A: Pre-2018 mortgage (grandfathered)
Scenario B: Post-2017 mortgage
Refinancing considerations with grandfathered mortgages
Key factors affecting your limit
What you should do
1. Check your mortgage documents to confirm your origination date
2. Calculate refinancing costs including the loss of grandfathered status
3. Consider the total tax impact before refinancing a grandfathered mortgage
4. Track both first and second mortgage balances against your applicable limit
Use our refund estimator to see how mortgage interest deduction changes might affect your refund.
Key takeaway: Mortgages from before December 16, 2017 keep the $1 million deduction limit until refinanced, while newer mortgages are capped at $750,000.
*Sources: [IRS Publication 936](https://www.irs.gov/pub/irs-pdf/p936.pdf), Tax Cuts and Jobs Act of 2017*
Key Takeaway: Mortgages from before December 16, 2017 keep the $1 million deduction limit until refinanced, while newer mortgages are capped at $750,000.
Mortgage interest deduction limits by mortgage date and filing status
| Mortgage Origination | MFJ/Single Limit | MFS Limit | Status |
|---|---|---|---|
| Before 12/16/2017 | $1,000,000 | $500,000 | Grandfathered |
| After 12/15/2017 | $750,000 | $375,000 | Current limit |
| Refinanced (any date) | $750,000 | $375,000 | New limit applies |
| Home equity (qualifying) | Included in above limits | Included in above limits | Must improve home |
More Perspectives
Robert Kim, Tax Return Analyst
Best for homeowners who sold one home and bought another, affecting their deduction limits
How moving affects your mortgage interest deduction limit
When you sell your home and buy a new one, you lose any grandfathered mortgage status from your previous home. Your new mortgage will be subject to the current $750,000 deduction limit, regardless of when your previous mortgage originated.
Example: Moving from a grandfathered mortgage
Previous home (sold in 2026):
New home (purchased in 2026):
Moving-related mortgage considerations
Bridge loans: Short-term financing while buying/selling doesn't affect your permanent mortgage's deduction limit, but bridge loan interest may not be deductible.
Porting mortgages: Some lenders allow you to transfer your existing mortgage to a new property, potentially preserving grandfathered status in rare cases.
Timing strategies: If you have a grandfathered mortgage, consider the tax implications before moving to a more expensive area.
Cash-out refinancing when moving
If you do a cash-out refinance on your new home, remember that home equity debt only qualifies for the deduction if used for home improvements, not for other purposes like paying off credit cards or investing.
Key takeaway: Moving to a new home means your new mortgage gets the current $750,000 limit, even if your previous mortgage was grandfathered at $1 million.
Key Takeaway: Moving to a new home means your new mortgage gets the current $750,000 limit, even if your previous mortgage was grandfathered at $1 million.
Robert Kim, Tax Return Analyst
Best for new homeowners learning about current mortgage interest deduction rules
Mortgage interest deduction limits for new homeowners
As a first-time homebuyer in 2026, your mortgage interest deduction is capped at $750,000 in mortgage debt ($375,000 if married filing separately). This limit applies to the total of your first mortgage, second mortgage, and qualifying home equity debt.
Understanding the $750,000 limit practically
For most first-time buyers, the $750,000 limit won't be a concern. According to the National Association of Realtors, the median home price is well below levels that would require mortgages exceeding this limit in most markets.
Typical first-time buyer scenarios:
When the limit might affect first-time buyers
High-cost areas: In expensive markets like San Francisco, New York, or Los Angeles, even starter homes might push mortgages toward or over the $750,000 limit.
Jumbo loans: If you're getting a jumbo loan, part of your interest might not be deductible.
Future considerations: Even if your current mortgage is under the limit, remember this when considering future home equity loans or lines of credit.
Planning as a new homeowner
The mortgage interest deduction limit should not be a primary factor in how much house you can afford. Focus on your ability to make monthly payments and build equity rather than maximizing tax deductions.
Key takeaway: Most first-time buyers won't hit the $750,000 mortgage interest deduction limit, but those in high-cost areas should be aware of the cap.
Key Takeaway: Most first-time buyers won't hit the $750,000 mortgage interest deduction limit, but those in high-cost areas should be aware of the cap.
Sources
- IRS Publication 936 — Home Mortgage Interest Deduction
- Tax Cuts and Jobs Act of 2017 — Tax law changes including mortgage interest deduction limits
Related Questions
Reviewed by Michelle Woodard, Tax Policy 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.