Idaho · Mortgage Interest Deduction
Mortgage Interest Deduction in Idaho (2026)
Deduct interest paid on up to $750,000 of mortgage debt for your primary or secondary home. Idaho has a flat 5.3% income tax, so a Idaho filer's combined marginal rate on the next dollar at $65,988 of income is about 17.3% (12% federal + 5.3% ID).
2026 savings example for Idaho
Planning estimate for a single filer earning $65,988 (Idaho median household income in LevyIO's state dataset) who removes $5,000 from taxable income. Federal tax uses the 2026 IRS brackets after the $16,100 standard deduction; ID tax uses the state brackets in LevyIO's dataset and assumes the state follows the federal treatment.
Estimated total savings
$865
Federal savings
$600
$5,739 → $5,139 · 12% bracket
ID state savings
$265
$2,389 → $2,124 · 5.3% marginal
Combined marginal rate
17.3%
≈ $173 saved per $1,000 deducted
Statutory maximum for this item in LevyIO's dataset: $750,000.
Federal × Idaho marginal rates (2026, single)
Gross-income ranges include the federal standard deduction. The ID column is the state marginal rate at the midpoint of each range. The last column is the tax saved per $1,000 deducted at that combined rate.
| Federal bracket | Gross income (single) | ID marginal | Combined | Per $1,000 |
|---|---|---|---|---|
| 10% | $16,100 - $28,500 | 5.3% | 15.3% | $153 |
| 12% | $28,500 - $66,500 | 5.3% | 17.3% | $173 |
| 22% | $66,500 - $121,800 | 5.3% | 27.3% | $273 |
| 24% | $121,800 - $217,875 | 5.3% | 29.3% | $293 |
| 32% | $217,875 - $272,325 | 5.3% | 37.3% | $373 |
| 35% | $272,325 - $656,700 | 5.3% | 40.3% | $403 |
| 37% | Over $656,700 | 5.3% | 42.3% | $423 |
Eligibility & forms
Homeowners with mortgage on primary or secondary residence
- Must itemize deductions
- Mortgage on qualified home
- Limited to $750K mortgage debt
Federal forms: Schedule A, Form 1098
Idaho filing notes
Federal standard deduction automatically applies. Maximize the 60% capital gains exclusion on Idaho-sourced investments. Use the grocery credit. Retirement income is fully taxable.
Common mistakes: Forgetting PMI premiums; Not tracking home equity loan interest.
Frequently asked questions
How much can the Mortgage Interest Deduction save a Idaho taxpayer in 2026?
In LevyIO's example, a single filer with $65,988 of income (the Idaho median household income in our state dataset) who removes $5,000 from taxable income saves about $600 in 2026 federal tax (12% marginal bracket) plus about $265 in Idaho tax (5.3% state marginal rate), roughly $865 combined. It is a planning estimate computed from the 2026 IRS brackets and LevyIO's ID bracket data, not a survey figure.
What is the Idaho income tax rate for 2026?
Idaho has a flat 5.3% income tax. The ID standard deduction in LevyIO's dataset is $16,100 single / $32,200 married. Flat 5.3% above $4,811 (single). Uses federal taxable income. 60% Idaho capital gains exclusion. Grocery credit $120/person.
Who qualifies for the Mortgage Interest Deduction in Idaho?
Homeowners with mortgage on primary or secondary residence. The federal rules are the same in every state; the requirements are: Must itemize deductions; Mortgage on qualified home; Limited to $750K mortgage debt. Idaho filers should confirm on the ID return whether the state follows the federal treatment.
Which forms do I file to claim the Mortgage Interest Deduction?
Federal: Schedule A, Form 1098. Idaho: check the Idaho State Tax Commission instructions for the matching state schedule. Common mistakes: Forgetting PMI premiums; Not tracking home equity loan interest.
Mortgage Interest Deduction in other states
Sources
Reviewed 2026-09-17. Estimates are educational planning figures computed from the IRS 2026 inflation adjustments and LevyIO's state bracket dataset; they are not tax advice.