Proposition 136Income Tax Rate Limit
Read the full text of the measure: on this page or in the Blue Book (PDF, page 95)
In plain words
Colorado's state income tax rate is 4.4 percent today. Proposition 136 would write into state law that the rate can be no higher than 4.4 percent, starting January 1, 2027. It does not change anyone's tax today. source: Blue Book, p. 62
Before and after
| Question | Today | If Proposition 136 passes |
|---|---|---|
| State income tax rate for people and businesses | 4.4 percent | 4.4 percent |
| Is there a highest allowed rate in state law? | No | Yes, 4.4 percent, starting January 1, 2027 |
| Can the legislature or a citizen petition lower the rate? | Yes | Yes |
| Does raising the rate need a statewide vote? | Yes. The state constitution already requires it | Yes |
From the official analysis source: Blue Book, p. 62
Example
Illustration only: a person with $50,000 of taxable income (income after deductions) owes 4.4 percent, or $2,200, in state income tax today. If Proposition 136 passes, they still owe $2,200. source: Blue Book, p. 62
Biggest change
- If both this measure and Amendment 87 pass, they conflict: Amendment 87's rate for incomes over $500,000 would be above the 4.4 percent limit. The Blue Book says the exact outcome is unclear, and the legislature or a court would decide. source: Blue Book, p. 62
Who it affects most: Nothing changes for taxpayers now. It matters most if Amendment 87, which would charge a higher rate on incomes over $500,000, also passes, because the two measures would conflict.
Cost to the state: None. The Blue Book says it does not change state or local government revenue or spending.
Our plain-words summary at an 8th-grade reading level. Every line points to its source.
Related case study: TABOR: voter control, public revenue, and Colorado's ballot choices (initial draft, not independently reviewed).
What your vote means
State law would say the income tax rate can be no higher than today's 4.4 percent, starting January 1, 2027.
The income tax rate stays at 4.4 percent, with no limit written into state law.
Our plain-words summary.
The Blue Book's official wording of YES and NO (tap to open)
YES: A “yes” vote on Proposition 136 establishes the current state income tax rate of 4.4 percent as the maximum rate.
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.
Why people want it, and why others object
Why this is on the ballot
- Citizens put this on the ballot by collecting signatures (a citizen initiative). It would change a state law (a statute), not the state constitution. The Blue Book says voters approved the current rate in 2022. source: Blue Book, p. 62
Why supporters want it
- 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. source: Blue Book, p. 62
Why opponents object
- 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. source: Blue Book, p. 62
Who backs each side
Most totals are through October 4, 2026 (Rocky Mountain Voice, Oct 6); some are as of September 21 (Colorado Politics). Spending grows until Election Day. These figures come from news reports of state campaign finance filings and were not checked line by line against the filings.
- No money specific to Proposition 136 was found on either side.
Sources: Rocky Mountain Voice, Oct 6, 2026 · Colorado Politics, Sept 25, 2026 · Colorado Secretary of State: committees for and against 2026 measures · TRACER campaign finance search
Supporter and opponent arguments are the official ones printed in the Blue Book, written by the Legislative Council's nonpartisan staff after hearing from both sides. Who is registered for and against (Secretary of State) . We don't endorse either side.
At a glance
Our plain-words summary of the official Blue Book analysis. Every line points to its source.
Who it affects
- Individual income taxpayers in Colorado. (Blue Book, p. 62 )
- Corporations that pay Colorado income tax. (Blue Book, p. 62 )
- The state legislature and future citizen initiatives. They could still lower the rate. Raising it already needs voter approval. (Blue Book, p. 62 )
- Amendment 87, the graduated income tax on this ballot. Its proposed rate for incomes over $500,000 is higher than 4.4 percent, so the two measures conflict if both pass. (Blue Book, p. 62 )
How many: Unknown. The Blue Book does not give a count of taxpayers. Because the measure keeps today's 4.4 percent rate, it does not change anyone's tax bill.
Money: economic and budget impact
- No change to state revenue or spending. The Blue Book says the measure has no fiscal impact. (Blue Book, p. 62 )
- No change to local government revenue or spending. (Blue Book, p. 62 )
- Taxpayers: the income tax rate stays at the current 4.4 percent of taxable income. It becomes the maximum rate starting January 1, 2027. (Blue Book, p. 62 )
- No effect on TABOR refunds is listed. (Blue Book, p. 62 )
State law would set 4.4 percent as the highest income tax rate for individuals and corporations, starting January 1, 2027. Today's rate does not change. The process for changing the rate stays the same, and any rate increase still needs voter approval. This is a statute, so the legislature can amend it. If Amendment 87 also passes, the outcome is unclear and the legislature or a court will decide how to resolve the conflict.
The income tax rate stays at 4.4 percent, with no new limit in state law. The state constitution still requires voter approval for any tax rate increase.
Not yet known
- How the conflict would be resolved if both Proposition 136 and Amendment 87 pass, and what that would cost.
- Whether the measure has any effect after the 2026 election, since future voter-approved increases could override it. The Blue Book states this only as an argument.
Can it actually be enforced?
Short answer: Limited. It only caps the income tax rate at today's 4.4 percent. It is a statute, so later voters or the legislature can change it, and its main real-world effect may be on Amendment 87 if both pass, which a court or the legislature would sort out.
- This is a change to state statute, not the constitution. The legislature or a citizen initiative could change it later. (Blue Book, p. 62 )
- Tax rate increases already need voter approval under the Colorado Constitution (TABOR, Article X, Section 20). The Blue Book says Proposition 136 does not change that process. Opponents argue any future voter-approved increase would override it. (Blue Book, p. 62 )
- Conflict with Amendment 87: Amendment 87 would set a rate above 4.4 percent for income over $500,000. If both pass, the Blue Book says conflicts are generally settled by the measure with more votes, but the exact outcome is unclear and the legislature or a court will decide. (Blue Book, p. 62 )
- Amendment 87 changes the Colorado Constitution, while Proposition 136 is a statute. The Blue Book does not say how that difference would matter in the conflict. (Blue Book, p. 62 )
- No federal issue applies. The state sets its own income tax rates. (Blue Book, p. 62 )
Not yet known
- How a court would weigh a constitutional amendment against a statute passed on the same day, and whether vote totals would matter in that case.
This is our reading of the cited law, not legal advice. Court outcomes are uncertain.
Official ballot wording
Official ballot wording, word for word (tap to open)
The ballot title, word for word from the 2026 Blue Book.
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?
The official analysis
The full Blue Book analysis, word for word (tap to open)
Everything in this section is quoted from the nonpartisan Legislative Council's 2026 State Ballot Information Booklet (the Blue Book). Charts are described in words. Read the full Blue Book (PDF)
Proposition 136 proposes amending the Colorado statutes to:
- set a 4.4 percent limit on the state income tax rate for individual and corporate taxpayers.
Summary and Analysis of Proposition 136
What does Proposition 136 do?
The measure limits the state income tax rate for individuals and corporations to the current rate of 4.4 percent of taxable income beginning on January 1, 2027.
Does Proposition 136 change the current income tax rate?
No, the measure does not alter the current 4.4 percent state income tax rate. It creates a state law setting this rate as the maximum beginning on January 1, 2027.
Does Proposition 136 prevent any future changes to the state income tax rate?
No, Proposition 136 will not change the process for adjusting Colorado’s income tax rate. The state legislature or a citizen initiative may reduce the state income tax rate. The Colorado Constitution already requires that any tax rate increases be approved by voters.
What happens if Proposition 136 and Amendment 87 both pass?
Amendment 87 creates a graduated income tax, where higher tax rates are applied to higher incomes and lower tax rates are applied to lower incomes earned by a household or business. If both Amendment 87 and Proposition 136 are approved by voters, the proposed rate for incomes over $500,000 in Amendment 87 would be higher than the 4.4 percent limit in Proposition 136. 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. The state legislature or a court will determine how to resolve any conflicts.
Argument For Proposition 136
1) 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.
Argument Against Proposition 136
1) 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.
Information about the organizations supporting and opposing this measure is available on the Colorado Secretary of State's website:
www.coloradosos.gov/pubs/elections/Initiatives/ballot/contacts/2026.html
Fiscal Impact of Proposition 136
The measure limits the state income tax rate to no higher than the current rate of 4.4 percent. This results in no change to state or local government revenue or spending. For this reason, the measure has no fiscal impact.
Latest news
Recent reporting from a range of outlets, newest first. We link to it; we don't endorse it.
- 2026-10-02 The Colorado Sun: Proposition 136 explained: Colorado income tax limit could block higher taxes on rich
- 2026-10-02 Colorado Politics: Proposition 136
- 2026-09-25 CPR News: Proposition 136: Income Tax Rate Cap
Coverage of all the statewide measures
- 2026-10-06 Rocky Mountain Voice: What's on your 2026 Colorado ballot: all 14 statewide measures
- 2026-09-25 Colorado Politics: Major donors fuel Colorado ballot measure fights across the state
- 2026-09-25 CPR News: 2026 Colorado state ballot measures voter guide
Full text of the measure
Word for word from the Blue Book, page 95 (PDF ). Where the measure changes existing statutes, new wording is in CAPITAL LETTERS, as in the printed booklet.
Show the full text
Be it Enacted by the People of the State of Colorado:
SECTION 1. In Colorado Revised Statutes, add 39-22-102.5 as follows: 39‑22‑102.5. Maximum Tax Rate. Starting January 1, 2027, neither the individual income tax rate nor the corporate income tax rate may exceed 4.4% of a taxpayer’s federal taxable income.
SECTION 2. Effective date. This measure is effective upon proclamation of the Governor and applicable to the tax year beginning January 1, 2027 and all future tax years thereafter.
Read more
- 2026 Blue Book (PDF) , including the full legal text of the measure
- Colorado Secretary of State: who is registered for and against
- TRACER: Colorado campaign finance filings
What people are saying
Official campaign accounts on each side, and public posts. Links only: nothing here loads from social media sites. We link to posts; we don't endorse them.
No official campaign accounts listed yet.
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