MortgageCostsGuide

Mortgage Interest Deduction in California

State income tax rate
13.3%
Itemized deductions allowed
✅ Yes

State-Level Mortgage Interest Deduction

California conforms to federal itemized deductions with a top rate of 13.3%, making the combined federal+state deduction one of the most valuable in the country for high-income homeowners. Note: California uses a 2015 IRC conformity date, so some federal TCJA changes may be handled differently.

Combined Federal + California Savings

If you paid $18,000 in mortgage interest last year and itemize on both returns, your combined tax savings would be approximately:

  • Federal (22% bracket): $3,960
  • California (13.3% rate): $2,394
  • Total estimated savings: $6,354

These are estimates based on a 22% federal bracket. Your actual savings depend on your specific tax situation.

Frequently Asked Questions

Keep reading

CalculatorMortgage Interest Deduction CalculatorRun your own numbers with California rates applied.GuideMortgage Interest Deduction by StateHow the federal rules interact with each state's conformity and limits.GuideIs a Home Equity Loan Tax Deductible?The 2018 rules, and the use test that decides whether your interest qualifies.GuideMortgage Points: What They Cost and When They Pay OffPoints are prepaid interest, and on a purchase they can be deducted in the year paid.

Rate reflects the top marginal state income tax rate for 2026 per the Tax Foundation. Whether a deduction helps depends on your full return, including whether itemizing beats the federal standard deduction. General information, not tax advice.