Colorado DUI & DWAI Laws Explained

By Javier Marín, Editor·Last reviewed September 2026·How we check this

Colorado's impaired-driving statute is unique in the country. Colorado Revised Statute § 42-4-1301 creates two distinct offenses — DUI at 0.08% BAC or higher and DWAI (Driving While Ability Impaired) at 0.05% to 0.079% BAC. Both go on the driving record, both carry license consequences, and both interact with the parallel administrative Express Consent revocation that the DMV runs separately from the criminal court.

The legal thresholds

DUI (adults 21+): 0.08% BAC.
DWAI (adults 21+): 0.05% to 0.079% BAC, or "the slightest degree" of impairment provable from officer testimony at any BAC level.
Drivers under 21: 0.02% to 0.049% triggers an Underage Drinking and Driving (UDD) administrative action.
Commercial drivers (CDL): 0.04% BAC.
Marijuana: 5 ng/mL active THC creates a permissible inference of impairment under § 42-4-1301(6)(a)(IV).
Persistent Drunk Driver (PDD): any BAC of 0.17% or higher, or two or more alcohol-related convictions in the last five years.

Express Consent and the 7-day window

Colorado's Express Consent statute (§ 42-4-1301.1) deems every driver to have consented to a chemical test when a peace officer has probable cause to believe the driver is impaired. After arrest, the officer typically takes the driver's license and issues a temporary driving permit. The driver has 7 calendar days from arrest to request an Express Consent hearing with the DMV. Miss the window and the revocation takes effect on the date stated on the order.

9 months revocation for a first BAC failure (0.08+).
1 year revocation for a first chemical-test refusal.
1 year for a second BAC failure within 5 years.
2 years for a second refusal.

First-offense criminal penalties

A first DUI in Colorado is a misdemeanor with the following exposure:

Jail: 5 days to 1 year (suspended on most first offenses without aggravating factors).
Fine: $600 to $1,000, plus surcharges that often add another $1,000-$1,500.
License revocation: 9 months under Express Consent (parallel to court action).
Public service: 48-96 hours.
Mandatory Level II Education and Therapy (alcohol education).
2-year probation.
Ignition Interlock Device for 9 months on the first BAC failure (longer for high BAC and refusals).
SR-22 financial responsibility filing for 3 years.

A first DWAI carries lighter penalties: 2 days to 6 months in jail, fine of $200-$500, no automatic license revocation (although 8 points on the record can trigger a points-based suspension), 24-48 hours public service, and Level II education.

Persistent Drunk Driver tier

Drivers convicted with a BAC at or above 0.17%, those convicted of refusal, and those with two or more alcohol-related convictions in five years receive a Persistent Drunk Driver (PDD) designation. PDD adds:

Mandatory ignition interlock for at least 2 years.
Level II Education and Therapy at the enhanced track.
Higher SR-22 minimums.
An alcohol-and-drug evaluation through a state-approved provider.

Ignition interlock devices

An IID is required after every alcohol-related license revocation in Colorado, regardless of first offense or repeat. The driver pays installation ($75-$150) and monthly monitoring ($60-$100). The device records every breath sample and uploads results to the manufacturer; failed tests or missed calibrations are reported to the DMV and can extend the IID period. Drivers eligible for early reinstatement may apply after as little as 30 days of revocation by installing the IID on every vehicle they own.

Marijuana DUI

Recreational marijuana has been legal in Colorado since 2014, but driving under its influence remains a DUI under the same statute. The 5 ng/mL active THC blood level creates a permissible inference of impairment — meaning a jury can find impairment without other evidence, but the defendant can argue it. Officers trained as Drug Recognition Experts (DREs) supplement chemical testing with field observations. Combination DUIs (alcohol plus marijuana) escalate quickly: a 0.05% BAC plus 5 ng/mL THC will be charged as DUI even though neither standing alone reaches the 0.08% threshold.

Aggravating factors

BAC at or above 0.17% (PDD designation).
Accident with property damage or injury.
Child under 18 in the vehicle.
Refusing the chemical test.
Driving on a previously revoked license.
Combined drug and alcohol impairment.

Repeat offenses

A second DUI within Colorado (no lookback window — lifetime priors count) brings mandatory minimum 10 days in jail, 1-year license revocation, and 2-year IID. A third DUI is mandatory minimum 60 days in jail. A fourth or subsequent DUI in Colorado is a Class 4 felony under § 42-4-1301(1)(a) — Colorado was one of the first states to make repeat DUI a felony at the fourth offense regardless of injury or other aggravators.

Reinstatement after the revocation runs through the suspended license process, with the IID-restricted license available before full reinstatement.