Colorado ends its flat tax: top earners will pay up to 8.4%

What was decided. Amendment 87 changes Colorado's constitution and brings back a graduated income tax for the first time since 1986, the Colorado Sun reports. Today everyone pays one 4.4% rate.

The new rates. Per the legislative council's Blue Book: up to $25,000 of taxable income 3.7%, $25,001 to $100,000 4.2%, $100,001 to $500,000 4.4%, $500,001 to $750,000 7.4%, $750,001 to $1 million 7.9%, above $1 million 8.4%. The rates also apply to businesses.

Who wins and who pays. The council estimates taxes go down for taxpayers with Colorado taxable income below $510,834 and up for those above it. The Colorado Sun calculates that a household with $75,000 of taxable income saves $275 a year.

The money. The council estimates extra revenue of $958.4 million in budget year 2026-27 and $1.972 billion in 2027-28, rising after that. It goes into a new Colorado Future's Account. The Colorado Sun says lawmakers can spend it on healthcare, schools and childcare.

The vote. Per the Denver Post, AP called the result just before 11 a.m. local time on Friday: 1,331,796 yes (51.4%) and 1,259,192 no (48.6%). Opponents conceded in the morning. Governor Jared Polis and Governor-elect Phil Weiser opposed the measure. The rival Proposition 136, which would have capped the rate at today's 4.4%, was heading for defeat, per the Denver Post.

What we do not know. Results are not yet officially certified. Whether there will be lawsuits, and how lawmakers will split the money, is still open.

Confirmed facts

• Amendment 87 replaces the 4.4% flat rate with six rates: 3.7%, 4.2%, 4.4%, 7.4%, 7.9% and 8.4%.^[1]
• The 8.4% rate applies to taxable income above $1,000,000; 3.7% applies to income up to $25,000.^[1]
• Taxes go down for taxpayers with Colorado taxable income below $510,834 and up for those above it.^[1]
• Extra state revenue: $958.4 million in budget year 2026-27 and $1.972 billion in 2027-28, credited to the Colorado Future's Account.^[1]
• The new rates apply to tax years starting on or after January 1, 2027.^[2]
• Colorado gets a graduated income tax for the first time since 1986.^[2]
• A household with $75,000 of taxable income pays $275 less a year.^[2]
• AP called the amendment on Friday with 51.4% yes: 1,331,796 to 1,259,192.^[3]
• Governor Jared Polis and Governor-elect Phil Weiser opposed the amendment.^[3]
• Proposition 136, which would have capped the rate at 4.4%, was losing by nearly 5.5 percentage points.^[3]

Implications

• ConfirmedFrom 2027 most Colorado residents pay slightly less income tax, while income above $510,834 is taxed more.
• Our readingSome wealthy residents and companies may weigh moving, but only data will show if that happens. This is our reading.
• Our readingOther flat-tax states will watch Colorado as a test case. This is our reading.

Still unknown

• When results are officially certified
• Whether the amendment faces lawsuits
• How lawmakers will split the new money

Who it affects

United States. Colorado residents and businesses, especially those earning over $500,000, and anyone following US taxes

Sources

1. Colorado Legislative Council: Amendment 87: Graduated Income Tax (2026 Blue Book) September 1, 2026 · official
2. The Colorado Sun: Colorado voters approve Amendment 87, imposing higher income taxes on top earners November 6, 2026 · media
3. The Denver Post: Amendment 87 supporters declare victory for major rewrite of Colorado's tax code, affecting all taxpayers November 6, 2026 · media