What is the Colorado state income tax rate in 2026?
Colorado taxes income at a flat 4.40% in 2026. Example: a married couple, both 70, with $40,000 of Social Security, a $30,000 private pension and $30,000 of IRA withdrawals ($100,000 in all; the pension and IRA money split evenly between them) owes $0 of Colorado income tax (0.0% of their income) and $5,087 of federal tax; a single 62-year-old with $24,000 of Social Security, an $18,000 pension and $18,000 of IRA withdrawals ($60,000 in all) owes $715 to Colorado and $4,111 federal. The schedule, how Colorado treats each kind of retirement income, and its local taxes follow.
How Colorado taxes retirement income in 2026
| Standard deduction or personal exemption | $16,100 single, $32,200 married filing jointly, $24,150 head of household. The standard deduction includes $2,050 more for a single or head-of-household filer 65 or older, and $1,650 more for each spouse 65 or older on a married return. Above $300,000 of income the deduction (with its age and blindness amounts) is limited to $1,000 ($2,000 for a married couple filing jointly); the rest is added back. (Internal Revenue Service; rules) |
|---|---|
| Social Security | From age 65, fully subtracted at any income. From 55 to 64, fully subtracted when income is at or below $75,000 (single) and $95,000 (married filing jointly); above it, one $20,000 subtraction is shared with pension and annuity income, Social Security first. Below 55, only benefits received because the person entitled to them died qualify (up to $20,000). (Colorado Department of Revenue; rules) |
| Pensions, annuities and IRA/401(k) withdrawals | Pension, annuity and IRA/401(k) distributions get a subtraction of up to $24,000 from age 65, and up to $20,000 from age 55. The cap is reduced by the Social Security subtraction claimed; for filers 55-64 over the income threshold the $20,000 is shared with Social Security. Below 55: no subtraction ($0), except a death benefit up to $20,000; a survivor's military retirement pay takes the military subtraction or the death-benefit one, whichever is larger, not both. (Colorado Department of Revenue; rules) |
| Age 65 and older | The federal senior deduction is also taken against the state base: $6,000 for each taxpayer 65 or older, each reduced by 6% of income above $75,000 (single and head of household) or $150,000 (MFJ). (Internal Revenue Service; rules) |
| Capital gains | Net long-term gain is taxed as ordinary income. Short-term gains are ordinary income. (Colorado Department of Revenue; rules) |
Local income taxes: none in Colorado. The local income taxes the tax engine computes for 2026 are in Delaware, Indiana, Iowa, Kentucky, Maryland, Michigan, Missouri, New York, Ohio, Oregon and Pennsylvania.
Your whole 2026 return in Colorado, federal and state together, ends in a refund or an amount owed: 2026 tax return calculator (free) → What five typical retiree households owe or get back in Colorado and every other state: the 2026 tax return study.
Figures for 2026 from QuantCalc’s open tax engine (federal 2.6.1, state 1.28.0), for a full-year resident. An estimate, not tax advice: credits, itemized deductions and rules this page does not ask about change a real return. Every Colorado rule with its official sources: Colorado rules and sources.
In QuantCalc's 51-state planner study — one married couple, both 60, $2M, $80,000 a year to spend after tax, 10,000 paths per jurisdiction — the median path in Colorado pays $184,926 of federal and state income tax and Medicare IRMAA over 30 years, $20,278 of it Colorado state income tax, $22,329 more than in the 16 jurisdictions that charge this couple no state tax. That ranks #18 of 51 by lifetime tax (1 = lowest). The plan succeeds in 83.73% of paths. State tax is part of the optimization here — the playbook below shows the federal-state-ACA stack.
The CO verdict
For a retiree planning withdrawals in 2026, Colorado is a middle-of-the-road state for retirement taxation. One flat bracket, with a Social Security and pension subtraction that turns fully exempt at 65.
Colorado has no dollar-capped retirement-income exclusion, so every converted dollar enters the state tax base. The marginal cost of a conversion here is the federal bracket plus the state rate plus, below 65, whatever premium tax credit crossing the 400% FPL cliff would cost you.
Worked example: $30k Roth conversion in Colorado
Consider a married couple age 58 in Colorado with $75,000 of wages (their MAGI), both on ACA Marketplace coverage. They want to convert $30,000 from a traditional IRA to a Roth. The Colorado state tax on that conversion is $0 — Colorado's retirement-income exclusion covers the whole conversion for this couple at this age. Federal income tax adds another $3,600 — the whole conversion is taxed in the federal 12% bracket. And because the conversion pushes their MAGI to $105,000 — over the 400% FPL cliff of $84,600 — they lose their full ACA premium tax credit, $19,182 a year at Colorado's average benchmark Silver premium. Total cost of the $30,000 conversion: $22,782, or an effective 75.9% marginal rate. Each Colorado tax figure for a conversion on this page is QuantCalc's state tax engine run on the couple's whole 2026 Colorado return twice, without the conversion and with it, with every amount split evenly between the two spouses, so Colorado's own brackets, deductions, exemptions and credits are all applied. The federal-state-ACA stack matters in Colorado.
Cost breakdown
| Component | Amount |
|---|---|
| Federal income tax (12% bracket) | $3,600 |
| Colorado state income tax | $0 |
| ACA premium tax credit clawback | $19,182 |
| Total cost on $30,000 conversion | $22,782 (75.9% effective) |
Scenario B (moderate): cliff-aware $34.6k conversion in Colorado
A Colorado couple aged 60, both on Marketplace coverage with $50K wages converts $34,600, which lifts their MAGI to exactly the $84,600 400% FPL cliff: still eligible, and they keep a premium tax credit of $19,963 a year. One more dollar of conversion would cost all of it. State tax: $0 — Colorado's retirement-income exclusion covers the whole conversion for this couple at this age. Federal income tax added: $4,012 (the whole conversion is taxed in the federal 10%–12% brackets). ACA PTC preserved. Total cost: $4,012, or 11.6% effective. In moderate-tax states, the conversion size is bounded by both the IRMAA two-year lookback and the ACA cliff — not state tax alone.
What the planner's Monte Carlo says about Colorado
QuantCalc Research ran one married couple through QuantCalc's retirement planner in each of the 51 jurisdictions: both 60, $2,000,000 ($1,400,000 traditional, $600,000 Roth), a 60/40 portfolio, $80,000 a year to spend after tax for 30 years, no Social Security, 10,000 paths each. The planner's federal and state tax engines price every year, and it picks the withdrawals and Roth conversions. Here is Colorado beside the lowest- and highest-tax results:
| Metric | Colorado | No state tax (16 jurisdictions) | Oregon (highest) |
|---|---|---|---|
| Median lifetime tax, federal + state + IRMAA (30y) | $184,926 | $162,597 | $309,718 |
| State income tax (30y, sum of yearly medians) | $20,278 | $0 | $146,914 |
| State income tax in the first year (age 60) | $637 | $0 | $5,838 |
| 30-year success rate | 83.73% | 84.05% | 80.61% |
| Median balance at 90 | $2,113,337 | $2,153,150 | $1,801,272 |
| Rank by lifetime tax (of 51, 1 = lowest) | #18 | #1 | #51 |
Across all 51 jurisdictions the success rate runs from 80.61% to 84.05%: for this couple the state changes the tax bill far more than the odds of the money lasting. Dollars are today's dollars. Source: QuantCalc 51-State Retirement Monte Carlo (v2026.3, re-run 2026-10-12) — 510,000 planner paths, methodology and dataset released CC-BY-4.0. Every jurisdiction's row uses the same household and the same market paths; only the state of residence changes.
How Colorado treats capital gains in retirement
Colorado taxes long-term capital gains as ordinary income at the same top bracket rate (4.40%). That stacks on top of federal LTCG (0%/15%/20%) and the 3.8% NIIT for high earners. A 'free' federal 0% LTCG harvest still costs you up to 4.40% at the state level — meaningful in this jurisdiction, particularly during Roth-conversion years when your MAGI is already elevated.
Why the ACA cliff hits hard in Colorado
The 400% federal-poverty-level cliff is federal, not state-specific — but its dollar impact depends on the benchmark Silver-plan premium in your county. Colorado's Marketplace pricing and your household composition determine the size of the subsidy at risk. A couple aged 58 with MAGI of exactly $84,600 still has $18,226 a year of premium tax credit at Colorado's average benchmark Silver premium, and all of it is on the line. With the 2021–2025 enhanced credit expired, $1 of additional MAGI above 400% FPL eliminates the entire credit.
For 2026 the 400% FPL threshold is:
Roth conversion strategy for Colorado
The CO-specific playbook depends on tier:
- Identify your cliff distance. Compute MAGI from all income sources (wages, capital gains, interest, dividends, traditional withdrawals). Find your headroom under 400% FPL. Use the live cliff widget above for a quick check.
- Stay under the cliff if you can. In Colorado at 4.40%, the marginal cost of going over the cliff is federal tax + state tax + full PTC clawback. The break-even conversion size is smaller than in tax-free states.
- If you must go over, convert big. Once you've crossed the cliff, additional conversion dollars only cost federal + state tax (no incremental PTC loss). A "rip the bandage" conversion year can be efficient if you have many traditional dollars to move.
- Coordinate with capital gains and the 0% LTCG bracket. Colorado taxes long-term capital gains as ordinary income at the same top bracket rate (4.40%). That stacks on top of federal LTCG (0%/15%/20%) and the 3.8% NIIT for high earners. A 'free' federal 0% LTCG harvest still costs you up to 4.40% at the state level — meaningful in this jurisdiction, particularly during Roth-conversion years when your MAGI is already elevated.
- Plan ahead for IRMAA. The IRMAA Medicare premium surcharge has a 2-year lookback. A Colorado resident in their early 60s converting today will see IRMAA implications at 65. See RMD + IRMAA calculator for the lookback math.
State tax basics for Colorado retirees
| Question | Colorado |
|---|---|
| State income tax | 4.40% top marginal |
| Number of brackets | 1 |
| Social Security taxed | Yes (with thresholds) |
| 401(k) / Traditional IRA taxed | Yes |
| Retirement-income exclusion (couple) | None |
| Roth conversion draws that exclusion | Not applicable |
| State estate / inheritance tax | No |
| Retirement-friendliness tier | moderate |
| Notable feature | one flat bracket, with a Social Security and pension subtraction that turns fully exempt at 65 |
| 30-yr planner success rate | 83.73% |
| Median 30-yr tax, federal + state + IRMAA (rank) | $184,926 (#18/51) |
Model your full Colorado retirement scenario
Free Monte Carlo (100 paths per run; 10,000 with PRO) with state-specific tax engine, ACA cliff, Roth conversion optimizer, IRMAA lookback — free, no signup.
Run a free simulation →What a year-end move does to your Colorado and federal tax in 2026
Each move changes three bills at once: the federal return, the Colorado return and, for anyone on Medicare, the IRMAA surcharge the 2026 income sets for 2028. Example: a married couple, both 72, with a $40,000 pension, $50,000 of Social Security, a $30,000 IRA withdrawal and $10,000 of long-term gains already realized in 2026, the pension, the IRA money and the conversion split evenly between them on the state return. Each row is that year with one move made, against the same year without it (negative = less tax).
| Move (by December 31, 2026) | Federal tax | Colorado tax | IRMAA in 2028 |
|---|---|---|---|
| Convert $25,000 to a Roth IRA | $3,165 | $1,102 | $0 |
| Send $10,000 of the IRA withdrawal to charity as a QCD | −$1,200 | −$440 | $0 |
| Harvest a $5,000 loss against the year's gains | $0 | −$220 | $0 |
An estimate from QuantCalc’s open tax engine (federal 2.6.1, state 1.28.0) for the 2026 tax year. Not tax advice: your return depends on facts this page does not ask about, so check a move with your tax preparer or custodian before acting. IRMAA uses the 2026 tiers for two people on Medicare; the 2028 tiers are not published yet. How the engine computes each line, with its official source: federal, Colorado.
Related calculators and reading
- All-states retirement tax comparison — see Colorado alongside the other 50 jurisdictions.
- Colorado minimum wage 2026 — the hourly rate, scheduled increases and take-home pay after tax, from the official sources.
- State Retirement Tax Data 2026 — the per-jurisdiction rate, exclusion and Social Security figures behind this page, as CSV and JSON.
- Colorado side by side with another state's retirement taxes: Colorado vs Arizona.
- ACA Subsidy Cliff Optimizer — find the largest Roth conversion that keeps you under 400% FPL.
- Roth Conversion Optimizer — bracket-fill vs. fixed-amount strategy comparison.
- RMD + IRMAA Calculator — Medicare premium surcharge based on 2-year-old MAGI.
- Safe Withdrawal Rate Calculator — sequence-of-returns-aware withdrawal planning.
- Research: 51-State 30-year Monte Carlo (2026) — full ranking and dataset.
- Research: Monte Carlo ACA Cliff 2026 — 80,000-path study of the cliff cost.
FAQ
What is the Colorado state income tax rate in 2026?
Colorado taxes income at a flat 4.40% in 2026. The full schedule and Colorado's deductions are on this page (Colorado Department of Revenue; rules).
How much state income tax does a retiree pay in Colorado?
It depends on the kind of income. In 2026, a married couple, both 70, with $40,000 of Social Security, a $30,000 private pension and $30,000 of IRA withdrawals ($100,000 in all; the pension and IRA money split evenly between them) owes $0 of Colorado tax, and a single 62-year-old with $24,000 of Social Security, an $18,000 pension and $18,000 of IRA withdrawals ($60,000 in all) owes $715. Federal tax comes on top: $5,087 and $4,111.
Does Colorado tax Social Security benefits?
In some cases. From age 65, fully subtracted at any income. From 55 to 64, fully subtracted when income is at or below $75,000 (single) and $95,000 (married filing jointly); above it, one $20,000 subtraction is shared with pension and annuity income, Social Security first. Below 55, only benefits received because the person entitled to them died qualify (up to $20,000). (Colorado Department of Revenue; rules)
Does Colorado tax pensions, 401(k) and IRA withdrawals?
Pension, annuity and IRA/401(k) distributions get a subtraction of up to $24,000 from age 65, and up to $20,000 from age 55. The cap is reduced by the Social Security subtraction claimed; for filers 55-64 over the income threshold the $20,000 is shared with Social Security. Below 55: no subtraction ($0), except a death benefit up to $20,000; a survivor's military retirement pay takes the military subtraction or the death-benefit one, whichever is larger, not both. (Colorado Department of Revenue; rules)
Does Colorado have local income taxes?
No. No county, city or school district in Colorado levies an income tax that the tax engine computes for 2026.
Does Colorado tax Roth conversions?
Not for the couple in the worked example: a $30,000 conversion by a couple aged 58 with $75,000 of wages adds $0 of Colorado tax — Colorado's retirement-income exclusion covers the whole conversion for this couple at this age. The conversion is still a federal taxable event and can still trigger the 400% FPL ACA premium-tax-credit cliff. Each Colorado tax figure for a conversion on this page is QuantCalc's state tax engine run on the couple's whole 2026 Colorado return twice, without the conversion and with it, with every amount split evenly between the two spouses, so Colorado's own brackets, deductions, exemptions and credits are all applied.
What is Colorado's 30-year Monte Carlo retirement success rate?
In QuantCalc's 51-state planner study, one married couple (both 60, $2M, 60/40, $80,000 a year to spend after tax, 10,000 paths) succeeds in 83.73% of paths in Colorado; across all 51 jurisdictions the rate runs from 80.61% to 84.05%. The median path pays $184,926 of federal and state income tax and IRMAA over 30 years, $20,278 of it Colorado state income tax.
What is the ACA cliff in Colorado for 2026?
The ACA premium-tax-credit cliff is a federal threshold, not state-specific. For a household of two in 2026, it sits at 400% of the federal poverty level — $84,600. Crossing it by even $1 of MAGI eliminates the full subsidy now that the 2021-2025 enhanced credit has expired.
Is Colorado a good state to retire for tax purposes?
Colorado is a middle-of-the-road state for retirement taxation. One flat bracket, with a Social Security and pension subtraction that turns fully exempt at 65. In our planner study it ranks #18 of 51 by median lifetime tax (1 = lowest).
Does Colorado have a state estate or inheritance tax?
No — Colorado does not impose a state-level estate or inheritance tax.
How does Colorado tax capital gains?
Colorado taxes long-term capital gains as ordinary income at the same top bracket rate (4.40%). That stacks on top of federal LTCG (0%/15%/20%) and the 3.8% NIIT for high earners. A 'free' federal 0% LTCG harvest still costs you up to 4.40% at the state level — meaningful in this jurisdiction, particularly during Roth-conversion years when your MAGI is already elevated.
Last updated 2026-10-12. State income tax figures reflect the 2026 schedule published by Colorado's tax authority. ACA poverty-level figures: the 2025 HHS poverty guidelines for the 48 contiguous states and DC ($15,650 for one person, plus $5,500 for each additional person; 90 FR 5917), which set 2026 Marketplace coverage. Premium tax credit estimates use Colorado's average benchmark Silver premium. Monte Carlo numbers from the QuantCalc 51-state planner study (v2026.3, re-run 2026-10-12, CC-BY-4.0). This page is educational. Not tax, legal, or financial advice — consult a qualified advisor.