Idaho Capital Gains Tax Rate (2026)
Idaho capital gains tax overview
Idaho uses a flat 5.3% rate after legislative changes. No preferential long-term capital gains rate.
Federal + Idaho combined rates
Your total capital gains tax bill includes both layers — federal and state. Here is what an Idaho investor pays in 2026 for long-term gains:
| Federal Long-Term Rate | Idaho State Rate | Combined Rate | Plus NIIT (if applicable) |
|---|---|---|---|
| 0% | 5.30% | 5.30% | 9.1% |
| 15% | 5.30% | 20.3% | 24.1% |
| 20% | 5.30% | 25.3% | 29.1% |
The NIIT (Net Investment Income Tax) adds an extra 3.8% for taxpayers whose MAGI exceeds $200,000 (single) or $250,000 (married filing jointly). It is a federal tax only — Idaho does not have an equivalent.
How Idaho compares to other states
Idaho's top rate of 5.30% places it in the lower-middle tier of state capital gains taxation. For comparison:
- Zero-tax states (FL, TX, NV, etc.): 0% — total with 15% federal = 15%
- Low-rate states (AZ, IN, PA): 2.5–3.1% — total with 15% federal = 17.5–18.1%
- Idaho: 5.30% — total with 15% federal = 20.3%
- High-rate states (NY, NJ): 10.75–10.9% — total with 15% federal = ~26%
- California: 13.3% — total with 15% federal = 28.3%
Tax-reduction strategies for Idaho residents
With a top state rate of 5.30%, minimizing capital gains tax is particularly important in Idaho. Key strategies:
- Hold over 1 year for long-term federal rates (0/15/20%). Idaho does not offer a preferential state rate, but federal savings alone are often 7–17%.
- Tax-loss harvesting: Offset your gains with losses realized in the same year. A $20,000 loss offsets $20,000 of gains dollar-for-dollar, saving up to 25% ($5,060) on that $20,000 at top rates.
- 0% bracket planning: In lower-income years (retirement, sabbatical, between jobs), realize gains at the federal 0% rate. You still owe Idaho state tax, but eliminating the federal component is significant.
- Donate appreciated stock directly to charity or a donor-advised fund to avoid capital gains tax entirely while generating a charitable deduction for the full fair market value.
- Installment sales: If selling a business or real estate, structuring as an installment sale spreads the gain over multiple years, potentially keeping each year's gain in a lower bracket.
Detailed Idaho capital gains tax rules
Tax history and legal basis
Idaho taxes capital gains as ordinary income at a flat rate of 5.3% (effective 2024). Previously the state had a progressive system.
Exemptions and special treatment
Idaho does not offer a preferential capital gains rate or exclusion for investment gains. However, gains from the sale of qualifying Idaho farm or ranch land held 5+ years may qualify for special treatment. The federal Section 121 home sale exclusion applies.
Filing requirements
File Form 40 (resident). Idaho starts with federal taxable income and makes state adjustments. Estimated payments required if owing $500+. Filing deadline is April 15.
Recent changes and legislative updates
Idaho moved to a 5.3% flat tax in 2024, down from a progressive system topping out at 6%. The state has been aggressively cutting taxes as revenues exceeded projections. Idaho's low cost of living and no-estate-tax status make it attractive for relocating investors.
Worked example: $50,000 capital gain in Idaho
Here's exactly what an Idaho resident would owe on a $50,000 long-term capital gain with $80,000 in other income (single filer, 2026):
| Component | Amount | Notes |
|---|---|---|
| Capital gain | $50,000 | Long-term (held over 1 year) |
| Federal tax (15%) | −$7,500 | Based on $80,000 ordinary income + gain |
| Idaho state tax (5.3%) | −$2,650 | Applied to the full gain amount |
| Total tax owed | −$10,150 | Federal + state combined |
| You keep | $39,850 | 79.7% of your gain |
After both federal and Idaho state tax, you keep $39,850 of your original $50,000 gain. The effective combined rate is 20.3%.
Frequently asked questions — Idaho
Does Idaho tax short-term and long-term gains differently?
No — Idaho taxes both short-term and long-term capital gains as ordinary income at the same rates as wages. There is no state-level preferential rate for patience. The federal system, however, taxes long-term gains at 0/15/20% vs. up to 37% for short-term — a significant difference that applies regardless of state.
Do I need to file an Idaho tax return if I only have capital gains?
If you have capital gains income and meet Idaho's filing threshold, you are required to file an Idaho state income tax return. The threshold is typically similar to the standard deduction amount — check the ID Department of Revenue for the current year's filing requirements.
What if I moved to Idaho mid-year?
If you moved to Idaho during the year, you are a part-year resident. Idaho generally taxes capital gains realized while you were an Idaho resident. Gains realized before you moved may be taxable by your prior state. Keep detailed records of when each sale occurred relative to your move date.