Updated July 26, 2026. Quick answer (2026): Moving from Colorado to Idaho in retirement, the change is narrower than the headline rate comparison suggests. Four separate taxes change when you move — state income tax on withdrawals, state estate tax, state inheritance tax, and what probate costs your heirs. Most comparisons only price the first one.
Colorado vs Idaho: every tax that changes
| What changes | Colorado (leaving) | Idaho (arriving) |
|---|---|---|
| State income tax | flat 4.4% | flat 5.3% (cut from 5.695% by HB 40, 2025) |
| Social Security | Taxed only above deductions: age 65+ may subtract 100% of federally taxed Social Security; age 55-64 may subtract 100% if AGI ≤ $75,000 (single) / $95,000 (joint) (TY2025+), otherwise SS counts within the $20,000 pension/annuity subtraction cap. | not taxed (subtracted in full) |
| Pension / 401(k) / IRA | Pension/annuity subtraction (includes pensions, 401(k), IRA distributions, and taxable SS within cap): up to $20,000 (age 55-64) or $24,000 (65+) per taxpayer. | Pensions, 401(k), and IRA distributions generally fully taxable. |
| Estate tax | none | none |
| Inheritance tax | none | none |
| Probate fee model | reasonable-fee | reasonable-fee |
| Probate filing fee | $199 to open a decedent’s estate (informal or formal), ~$229 with equal justice surcharge — statewide per C.R.S. §13-32-102 and Colorado Judicial fee schedule (JDF 1) | varies by county |
| Small-estate limit | Collection of personal property by affidavit, C.R.S. §15-12-1201 — indexed annually by year of death: $80,000 (2023-2024 deaths), $86,000 (2025 deaths per official JDF 999 form, rev. April 2026); 2026 year-of-death figure not confirmed this session. Personal property only, 10-day wait, no court filing required. | $100,000 (net of liens/encumbrances) — collection of personal property by affidavit, Idaho Code §15-3-1201; personal property only, 30-day wait. Summary administration also available where spouse is sole beneficiary (§15-3-1205). |
Every cell is quoted from our statute-cited 51-jurisdiction dataset. Download the full dataset as CSV.
1. What changes on your annual tax bill
Colorado: Pension/annuity subtraction (includes pensions, 401(k), IRA distributions, and taxable SS within cap): up to $20,000 (age 55-64) or $24,000 (65+) per taxpayer. Idaho: Pensions, 401(k), and IRA distributions generally fully taxable. Compare the two schedules directly rather than the headline top rates, because exclusions and age thresholds usually matter more than the rate.
2. What changes at death: state estate tax
Neither state levies an estate tax. Colorado: none Idaho: none Only the federal estate tax applies.
3. What changes at death: state inheritance tax
Neither state levies an inheritance tax. Colorado: none Idaho: none
4. The one nobody prices: what probate costs your heirs
Colorado uses a reasonable-fee fee model (UPC state: reasonable compensation (C.R.S. §15-12-719); no percentage schedule.); Idaho uses a reasonable-fee model (UPC state: reasonable compensation (Idaho Code §15-3-719); no percentage schedule.). Filing fees — Colorado: $199 to open a decedent’s estate (informal or formal), ~$229 with equal justice surcharge — statewide per C.R.S. §13-32-102 and Colorado Judicial fee schedule (JDF 1) Idaho: varies by county
Full detail: probate cost by state and small-estate limits by state.
Probate cost in each state, specifically
Colorado uses a “reasonable fee” standard with no schedule, and its small-estate route does not clear a solely owned house. Idaho uses a “reasonable fee” standard with no schedule, and its small-estate route does not clear a solely owned house. Both states land in the same bucket on that question. Full figures with the governing statute, the court filing fee and the small-estate threshold: Colorado probate cost and Idaho probate cost.
Four taxes, two states, one order of operations
Everything above changes together: what Colorado stops taking on withdrawals, what Idaho does not take at death, and what probate costs in each. The order you do things in — when you establish domicile, when you convert, when you retitle property — changes the total, and some of it cannot be undone afterwards. If a move is genuinely on the table, here is what to look for in an advisor who knows both Colorado and Idaho. If you would rather price it yourself first, the two-state comparison tool is free and asks for no email.
Will Colorado still tax me after I move to Idaho?
Not on your retirement withdrawals, once you genuinely change domicile — but that is a harder test than a change of address, and what you leave behind stays in reach.
- Domicile is a test, not a mailing address. A departing state can and does audit residency. Days present, voter registration, driver’s licence, where your doctors and advisers are, and where you keep what you value all count.
- A Roth conversion is taxed where you live in the year you convert. Sequencing a conversion after establishing the new domicile is often worth more than the annual saving — see how all 51 jurisdictions tax Roth conversions.
Full state detail
Every figure above is summarized. The complete statute-cited breakdown for each state: Colorado retirement taxes and Idaho retirement taxes. To compare any other pair, start at the retirement tax relocation hub.
Widen the comparison
This page prices one corridor. To see every destination Colorado retirees consider and every origin state moving to Idaho, start there instead. For any pair not covered, the retirement tax comparison tool runs all 51 jurisdictions, and the probate cost calculator works out what settling the estate costs in each.
Talking this through
Relocation timing, Roth conversion sequencing and estate exposure interact, and the order you do them in changes the total. If you want a second opinion, understand what it should cost first — see our advisor cost guide.
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Cite or share this comparison
Suggested citation: Clear Money Guide, “Colorado to Idaho Retirement Taxes (2026),” statute-cited; clearmoneyguide.com/colorado-to-idaho-retirement-taxes/. Free to cite with attribution. Download the full dataset as CSV, or contact contact@clearmoneyguide.com for custom cuts.
Primary sources
- C.R.S. § 39-22-104(4)(f), (g), (y)
- CDOR Income Tax Topics: Social Security, Pensions, and Annuities
- Idaho Code § 63-3022A
- Idaho State Tax Commission: Idaho Retirement Benefits Deduction
- Form 39R Part B
- Colo. Rev. Stat. §15-12-719
- Colo. Rev. Stat. §15-12-1201
- Colo. Rev. Stat. §13-32-102
- Idaho Code §15-3-719
- Idaho Code §15-3-1201
Methodology: every figure is quoted from Clear Money Guide’s statute-cited 51-jurisdiction datasets, compiled from state statutes, session laws and revenue-department publications and adversarially verified in July 2026. Nothing here is personalized tax or legal advice. Confirm your own facts with a qualified adviser before you move.