Start with Colo. Rev. Stat. § 42-4-1301. In Colorado, BAC limits: 0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21; DWAI may apply from about 0.05%. A first offense: First-offense DUI/DWAI is typically a misdemeanor with fines, possible jail, probation, useful public service, alcohol education, and license restraints. Felony threshold: A fourth DUI/DWAI with qualifying priors can be a felony; vehicular assault/homicide while DUI are separate felonies. That is the question this guide answers for DUI penalties. Lookback: Prior alcohol convictions enhance penalties; felony DUI and persistent-drunk-driver rules use defined Title 42 windows.. Ignition interlock: Ignition interlock is required for many DUI offenders, especially high-BAC, refusal, and repeat cases.
Blood alcohol limits in Colorado
0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21; DWAI may apply from about 0.05%
Lookback window for prior offenses
Prior alcohol convictions enhance penalties; felony DUI and persistent-drunk-driver rules use defined Title 42 windows.
How the Colorado rule applies
Apply the Colorado authorities in order. The facts are simplified so the statute and the standard are visible.
A driver in Colorado is charged with a first impaired-driving offense and wants to know what the statute actually sets.
- Start with the alcohol limits: 0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21; DWAI may apply from about 0.05%
- Read the first-offense range: First-offense DUI/DWAI is typically a misdemeanor with fines, possible jail, probation, useful public service, alcohol education, and license restraints.
- Ask when the charge becomes a felony: A fourth DUI/DWAI with qualifying priors can be a felony; vehicular assault/homicide while DUI are separate felonies. Lookback: Prior alcohol convictions enhance penalties; felony DUI and persistent-drunk-driver rules use defined Title 42 windows.
- Interlock: Ignition interlock is required for many DUI offenders, especially high-BAC, refusal, and repeat cases.
Colorado charges DUI or the lesser DWAI under § 42-4-1301. Express-consent refusals trigger separate DMV hearings. Criminal court and the DMV run on parallel tracks.
First-offense penalties
First-offense DUI/DWAI is typically a misdemeanor with fines, possible jail, probation, useful public service, alcohol education, and license restraints.
When a Colorado DUI becomes a felony
A fourth DUI/DWAI with qualifying priors can be a felony; vehicular assault/homicide while DUI are separate felonies.
Ignition interlock and license consequences
Ignition interlock is required for many DUI offenders, especially high-BAC, refusal, and repeat cases.
How a typical Colorado DUI case unfolds
Colorado charges DUI or the lesser DWAI under § 42-4-1301. Express-consent refusals trigger separate DMV hearings. Criminal court and the DMV run on parallel tracks.
Related Colorado guides
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- Child custody and parenting time in Colorado
- Security deposit return in Colorado
Case law: DUI penalties in Colorado
The PEOPLE OF THE STATE OF COLORADO, Plaintiff-Appellee, v. Gary Dean MERSMAN, Jr., Defendant-Appellant
…ng him guilty of aggravated driving with a revoked license, driving under the influence of alcohol, and driving under restraint. We affirm in part, vacate in part, and remand with directions to correct the mittimus. In August 2003, Mersman borrowed a friend’s vehicle to visit his ex-girlfriend, G.D. At the time, G.D. lived in a mobile home owned by R.H. When Mersman arrived at…
Practitioners open The PEOPLE OF THE STATE OF COLORADO, Plaintiff-Appellee, v. Gary Dean MERSMAN, Jr., Defendant-Appellant when Colorado DUI penalties turns on the distinction in this sentence: "We affirm in part, vacate in part, and remand with directions to correct the mittimus. In August 2003, Mersman borrowed a friend’s vehicle to visit his ex-girlfriend, G.D. At the time, G.D. lived in a mobile home owned by R.H." Do not lift it out of the facts the court was deciding.
The People of the State of Colorado v. Donald Earl Smith
The People of the State of Colorado v. Donald Earl Smith, 182 Colo. 228 (1973)
…ranted the motion as it related to the misdemeanor count of driving under the influence. 1967 Perm.Supp., C.R.S.1963, 13-5-30(3)(c). On interlocutory appeal we affirmed the trial court ruling, in People v. Smith, 175 Colo. 212, 486 P.2d 8. After the jury was impaneled and sworn, the district attorney moved the court to dismiss the misdemeanor count of driving under the influenc…
Colorado opinions such as The People of the State of Colorado v. Donald Earl Smith are cited where DUI penalties is disputed. The court stated: "Perm.Supp., C.R.S.1963, 13-5-30(3)(c). On interlocutory appeal we affirmed the trial court ruling, in People v. Smith, 175 Colo. 212, 486 P.2d 8." That is the language to brief; the rest of the decision supplies the procedural posture.
The People of the State of Colorado v. Jimmy Billy Sanchez
The People of the State of Colorado v. Jimmy Billy Sanchez, 173 Colo. 188 (1970)
…dant was charged with the felony of causing an injury while driving under the influence of intoxicating *190 liquor contrary to the provisions of C.R.S. 1963, 40-2-11. In connection with the investigation of the case, while the defendant was in custody of the police, he was advised of his rights under the Colorado implied consent law, 1967 Perm. Supp., C.R.S. 1963, 13-5-30(3) (…
On DUI penalties, The People of the State of Colorado v. Jimmy Billy Sanchez speaks to the Colorado dispute in this passage: "C.R.S. 1963, 40-2-11. In connection with the investigation of the case, while the defendant was in custody of the police, he was advised of his rights under the Colorado implied consent law, 1967 Perm. Supp., C.R.S." The surrounding opinion shows how the court applied that language to the record.
Peter HALTER, Plaintiff-Appellant, v. DEPARTMENT OF REVENUE OF THE STATE OF COLORADO, MOTOR VEHICLE DIVISION
…ormance on the roadside sobriety tests, he was arrested for driving under the influence (DUI). Suspecting that plaintiff was impaired by alcohol, the arresting officer then gave plaintiff his choice of the testing alternatives applicable under the express consent statute for driving under the influence of alcohol (DUI-alcohol), and plaintiff chose to take a breath test. See § 4…
Peter HALTER, Plaintiff-Appellant, v. DEPARTMENT OF REVENUE OF THE STATE OF COLORADO, MOTOR VEHICLE DIVISION is worth reading on Colorado DUI penalties because the court put the point in its own words: "UI). Suspecting that plaintiff was impaired by alcohol, the arresting officer then gave plaintiff his choice of the testing alternatives applicable under the express consent statute for driving under the influence of alcohol (DUI-alcohol), and plaintiff chose to take a breath test." Use that passage as the starting point, then read the facts that precede it.
Leslie RENCK, Plaintiff-Appellant, v. MOTOR VEHICLE DIVISION Department of Revenue, State of Colorado
…ty” test, and then advised him that he was under arrest for driving under the influence of alcohol. After being arrested, Renck was advised pursuant to the implied consent act, § 42 — 4-1202(3), C.R.S.1973. When asked to submit to a blood alcohol determination test, he stated that he “didn’t think it was necessary.” The “D.U.I.” officer notified the department by sworn report t…
Practitioners open Leslie RENCK, Plaintiff-Appellant, v. MOTOR VEHICLE DIVISION Department of Revenue, State of Colorado when Colorado DUI penalties turns on the distinction in this sentence: "After being arrested, Renck was advised pursuant to the implied consent act, § 42 — 4-1202(3), C.R.S.1973. When asked to submit to a blood alcohol determination test, he stated that he “didn’t think it was necessary.” The “D.U.I." Do not lift it out of the facts the court was deciding.
The PEOPLE of the State of Colorado, Plaintiff-Appellant, v. Ranee Randall REYNOLDS, Defendant-Ap — Vollack, J
…t results. I. Reynolds was charged with vehicular assault,1 driving under the influence of alcohol,2 driving with excessive alcohol content,3 and reckless driving.4 Reynolds moved to suppress several items of evidence, including, inter alia, the results of the blood alcohol test performed on him at the hospital. On November 21, 1994, the Yuma County District Court held a suppre…
Colorado opinions such as The PEOPLE of the State of Colorado, Plaintiff-Appellant, v. Ranee Randall REYNOLDS, Defendant-Ap — Vollack, J are cited where DUI penalties is disputed. The court stated: "I. Reynolds was charged with vehicular assault,1 driving under the influence of alcohol,2 driving with excessive alcohol content,3 and reckless driving." That is the language to brief; the rest of the decision supplies the procedural posture.
Key takeaways
- BAC limits: 0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21; DWAI may apply from about 0.05%
- Lookback period: Prior alcohol convictions enhance penalties; felony DUI and persistent-drunk-driver rules use defined Title 42 windows.
- First-offense range: First-offense DUI/DWAI is typically a misdemeanor with fines, possible jail, probation, useful public service, alcohol education, and license restraints.
- Felony threshold: A fourth DUI/DWAI with qualifying priors can be a felony; vehicular assault/homicide while DUI are separate felonies.
- Ignition interlock: Ignition interlock is required for many DUI offenders, especially high-BAC, refusal, and repeat cases.
- Primary authority: Colo. Rev. Stat. § 42-4-1301.
Frequently asked questions
What is the legal BAC limit in Colorado?
0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21; DWAI may apply from about 0.05%
Is a first DUI a felony in Colorado?
A fourth DUI/DWAI with qualifying priors can be a felony; vehicular assault/homicide while DUI are separate felonies.
Will I need an ignition interlock device?
Ignition interlock is required for many DUI offenders, especially high-BAC, refusal, and repeat cases.
This guide covers Colorado impaired-driving law as of 2026. Sentencing grids, administrative DMV rules, and local diversion programs change — verify the live statute and speak with counsel about your charging document.