Gallagher Is Gone: How Colorado's Property Tax Overhaul Changes Your Bill

If your property tax bill has felt like a moving target the last few years, you're not imagining it. Colorado has rewritten the residential property tax formula repeatedly since 2020, and the changes explain both why bills spiked and why appealing your valuation matters more than it used to.

The Gallagher era (1982–2020)

For nearly four decades, the Gallagher Amendment locked residential property into a fixed share of the statewide tax base. As home values grew faster than commercial property, the residential assessment rate ratcheted down automatically — from 21% in the 1980s to 7.15% by 2019. Homeowners were structurally protected from value spikes.

2020: voters repeal Gallagher

Amendment B froze assessment rates in place and removed the automatic ratchet. The timing mattered enormously: Colorado home prices then surged, and when the 2023 reassessment captured that run-up, residential values jumped 30–40%+ across much of the Front Range with no Gallagher mechanism to soften the blow.

2022–2023: emergency relief, twice

• **SB22-238** trimmed the residential rate to 6.765% for 2023 and knocked $15,000 off taxable actual value.
• Proposition HH (a larger rework tied to TABOR refunds) failed at the November 2023 ballot.
• Days later, a special legislative session (SB23B-001) deepened 2023 relief: a 6.7% rate and a $55,000 value reduction for that year.

2024: a longer-term framework — and split rates

In 2024 the legislature passed a bipartisan deal (SB24-233, adjusted by HB24B-1001 in a special session that headed off two ballot measures) that did three big things: modestly lowered residential rates going forward, added growth limits on how fast local property tax revenue can rise, and — the part most homeowners notice — split the residential assessment rate in two: one rate for school district taxes and a lower one for everything else. That's why your county now shows two "assessed values" for the same house. Current rates are published by the Colorado Division of Property Taxation.

What all this means for your bill

• Rate relief helped, but values dominate. Legislative cuts shaved a few percent; reassessment value jumps added tens of percent. The value side is where your bill is decided.
• Your valuation is the one input you can directly challenge. Rates are statewide law and mill levies are set by districts and voters — but the assessor's estimate of your home is appealable every cycle, by right.
• Two-year stakes. A successful appeal locks in savings for the full reassessment cycle, and a lower base compounds into the next one.

The bottom line

Colorado's post-Gallagher system passes market swings straight into your bill, with the legislature patching the formula as it goes. The constant in every version of the formula is the assessor's actual value of your home — and that's the number we fight. Start with how appeals work, check whether your home shows the signs of overassessment, or get your free analysis and let us tell you straight whether you have a case.