Colorado Proposition 136: Set a 4.4% limit on the state income tax rate
What it does. Proposition 136 would set a 4.4 percent limit in state law on the income tax rate for individual and corporate taxpayers, beginning January 1, 2027. It would not change today’s 4.4 percent rate. It would not change the process for adjusting the rate: the Legislature or a citizen initiative may still reduce it, and the Colorado Constitution already requires voter approval of tax rate increases. Because it is a statute, Ballotpedia notes, the Legislature could amend or repeal it. The Blue Book says that if Proposition 136 and Amendment 87 (a graduated income tax) both pass, “the exact outcome is unclear.” [1] [2]
Official ballot question. Shall there be a change to the Colorado Revised Statutes capping the state income tax rate at 4.4% of federal taxable income for individuals and corporations? [1]
If you vote yes
A yes vote on Proposition 136 establishes the current state income tax rate of 4.4 percent as the maximum rate. [1]
If you vote no
A no vote on Proposition 136 keeps the current state income tax rate of 4.4 percent without establishing a new limit in statute. [1]
What it would cost
The Blue Book says the measure “results in no change to state or local government revenue or spending. For this reason, the measure has no fiscal impact.” [1]
Both sides
Strongest case for
The Blue Book argument for says “Proposition 136 reinforces voter support for maintaining the current state income tax rate. The current rate, overwhelmingly approved by voters in 2022, is fair and keeps Colorado’s tax rate among the lowest in the country.” [1]
The Independence Institute says “Colorado’s flat 4.4% tax rate remains competitive regionally, as it is lower than the flat and top rates of Utah, New Mexico, Idaho and Montana.” [2]
Michael Fields, executive director of Advance Colorado, says the measure is “a clear counter to the far left’s attempt to hike taxes in Colorado, price people out of the state we love, and drive business out. We’ll always fight to protect TABOR and keep our taxes low.” [2]
Strongest case against
The Blue Book argument against says “This initiative is designed to put Amendment 87 into legal jeopardy, causing confusion and a potentially costly legal battle to resolve. After the 2026 election, Proposition 136 has no effect, since raising tax rates already requires voter approval and any future approval would override this measure.” [1]
The Bell Policy Center says “This measure is only meaningful because it conflicts with the graduated income tax that is proposed in Amendment 87. The tax rate is already 4.4 percent and the constitution states that only a vote of the people can increase tax rates.” [2]
New Era Colorado says “Giant corporations and the wealthy should not pay the same income tax rate as people earning $50,000 a year.” [2]
What neither side is saying
Context that bears on what this measure does or who it affects but that the arguments above do not address. These are sourced facts, not arguments for or against the measure.
- What happens if both this measure and Amendment 87 pass. The Blue Book says that if both pass, the Amendment 87 rate for incomes over $500,000 “would be higher than the 4.4 percent limit in Proposition 136,” and that “Generally, when parts of voter-approved measures conflict, the policy outcome is determined by the measure that receives more votes. However, if both measures are approved by voters, the exact outcome is unclear.” It says the Legislature or a court would resolve any conflict. See our page on Amendment 87. [1]
Editorial context, not the opinion of We Elect. Each point is a fact we found in a source we opened and read; where sources disagree or data are missing, we say so. How we choose these.
Follow the money
Contributions reported by committees registered to support or oppose Proposition 136. Major donors are those who gave $100,000 or more; where fewer than three did, up to five of the largest listed donors giving $5,000 or more are shown.
Supporting (Yes)
Total raised $3,878,275
Committees
- Brighter Colorado $3,270,775
- Keep Colorado Affordable $607,500
- Colorado Union of Taxpayers $0
At least one of these committees also campaigns on Colorado Amendment 87, so its money cannot be split by measure.
Major donors
| Common Sense America | $2,000,000 |
| GOPAC Election Fund | $1,605,000 |
| Colorado Dawn | $100,000 |
Opposing (No)
Total raised $3,359,500
Committees
- Protect Colorado's Future $2,528,931
- Vote Common Sense $830,569
- Make Good Change $0
- People for a Fair Colorado $0
At least one of these committees also campaigns on Colorado Amendment 87, so its money cannot be split by measure.
Major donors
| Merle Chambers | $500,000 |
| Conservation Colorado | $490,724 |
| New Era Colorado Action Fund | $276,241 |
| Stand for Children, Inc. | $250,000 |
| Colorado WINS | $212,890 |
Reported contributions through Oct. 14, 2026, as compiled by Ballotpedia from state filings; the source lists each side’s top donors, not every donor. Figures are reported contributions and may be updated as new reports are filed. Amounts are rounded to the nearest dollar. Official filings: Colorado Secretary of State, TRACER.
Sources
- 2026 Blue Book: Proposition 136, Income Tax Rate Limit — Colorado Legislative Council Staff (Official state voter guide, 2026)
- Colorado Proposition 136, Establish 4.4% Cap on Individual and Corporate Income Tax Rates Initiative (2026) — Ballotpedia (Reference (quotes supporters and opponents), accessed 2026-10-28)
Editorial summary of arguments made by others, not the opinion of We Elect. Last reviewed 2026-10-28. How we write both sides.
We Elect is a Brunner Creative site. Editorial summary of arguments made by others, not the opinion of We Elect. Each side is written to be the strongest case its supporters would recognize, and every claim is tied to a source we opened and read.