Colorado voters face rival income tax plans pulling opposite ways

Why it matters

Voters are not choosing one tax plan from a menu. Separate yes votes could raise top rates, lock in a cap, or create a conflict the legislature or a court must sort out, while changing how much money is available for schools, health care and early childhood programs.

Six new brackets would replace one flat rate

Amendment 87 would replace Colorado's flat income tax, where one rate applies, with six graduated brackets beginning in tax year 2027, with rates rising as taxable income rises.

The official fiscal impact statement lists 3.7% for taxable income up to $25,000, 4.2% from $25,000 to $100,000 and 4.4% from $100,000 to $500,000. The upper brackets are 7.4% from $500,000 to $750,000, 7.9% from $750,000 to $1 million and 8.4% above $1 million.

A half a million dollars per year is the dividing line described for households and businesses that would see their tax bill go up versus those that would see it go down. The official analysis says the measure directs the money to public schools, health care and early childhood education and care.

Revenue estimates need a close read. CPR reported the initiative is expected to raise $2.7 billion a year, while legislative analysts estimate $958.4 million in the partial 2026-27 fiscal year and $1.972 billion in 2027-28, the first full fiscal year.

Proposition 136 would cap income tax at 4.4%

Proposition 136 would set a 4.4% ceiling for Colorado state individual and corporate income tax rates starting Jan. 1, 2027, keeping the individual rate from rising above where it is now.

Advance Colorado brought Proposition 136 as the rival measure from opponents of the graduated income tax proposal, and the group is also against Amendment 87. Advance Colorado brought a number of Colorado's 14 ballot measures, including the tax cap.

The cap would matter most if lawmakers or voters later sought a higher rate. It directly collides with Amendment 87's upper brackets, which rise above 4.4%, making the two measures competing tax visions on the same ballot rather than parts of one plan.

Democrats split as campaign reaches neighborhoods

Former U.S. Sen. Ken Salazar and Gov. Jared Polis, both high-profile Democrats, have weighed in against Amendment 87, while many other Democrats back it, including Rep. Lorena Garcia of Adams County.

Garcia helped gather signatures for the measure and attended a rally supporting it at a Ballots and Beers event at Denver's Occidental bar on Oct. 21, 2026. That split sits inside a loud campaign built around a 196-word ballot question, with television spots, mailers and social media ads, an online tax calculator and an ongoing court battle.

Opposition has also gone door to door. Angel Merlos, with the LIBRE Initiative, held 'vote no on Amendment 87' flyers while canvassing a Thornton neighborhood on Oct. 22, 2026, for Gabe Evans, the incumbent Republican candidate for Colorado's 8th Congressional District. Advance Colorado President Michael Fields reiterated that the measure will be bad for the state's economy.

Voting yes on both would force another decision

The legislature's official 2026 State Ballot Information Booklet says that if both measures pass, they conflict and 'the outcome is unclear,' leaving the question for the General Assembly or a court.

The booklet notes that when approved measures conflict, the one receiving more votes generally governs. It does not promise that approving both would produce a blended system, and the official analyses explicitly leave the conflict for a later legal or legislative determination.

For now, each measure gets its own yes-or-no vote, and voters can approve one, both or neither. The next decision point comes after those separate votes are counted, when the legislature or a court may have to say which tax direction controls if both pass.