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DUI Penalties in Connecticut

September 28, 2026 · LawDiver Research Team

BAC limits: 0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21. A first offense: First-offense OUI is typically a misdemeanor with fines, possible jail (often suspended with probation), license suspension, and ignition-interlock requirements. Felony threshold: A third OUI within 10 years is a felony; OUI causing serious injury or death can also be charged as a felony. That is what separates Connecticut DUI penalties from a generic national summary. Read Conn. Gen. Stat. § 14-227a before the background sections below. Lookback: Prior convictions within 10 years enhance penalties for subsequent operating-under-the-influence offenses.. Ignition interlock: Ignition interlock is mandatory for most OUI offenders as a condition of restoring driving privileges.

Lookback window for prior offenses

Prior convictions within 10 years enhance penalties for subsequent operating-under-the-influence offenses.

First-offense penalties

First-offense OUI is typically a misdemeanor with fines, possible jail (often suspended with probation), license suspension, and ignition-interlock requirements.

When a Connecticut DUI becomes a felony

A third OUI within 10 years is a felony; OUI causing serious injury or death can also be charged as a felony.

A concrete Connecticut scenario

Here is one way the Connecticut pieces fit together. Change any fact and the statute may point somewhere else.

A driver in Connecticut 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
Read the first-offense range: First-offense OUI is typically a misdemeanor with fines, possible jail (often suspended with probation), license suspension, and ignition-interlock requirements.
Ask when the charge becomes a felony: A third OUI within 10 years is a felony; OUI causing serious injury or death can also be charged as a felony. Lookback: Prior convictions within 10 years enhance penalties for subsequent operating-under-the-influence offenses.
Interlock: Ignition interlock is mandatory for most OUI offenders as a condition of restoring driving privileges.

Connecticut OUI under § 14-227a triggers both criminal prosecution and DMV administrative per se suspension. Alcohol Education Program diversion may be available for eligible first offenders.

Ignition interlock and license consequences

Ignition interlock is mandatory for most OUI offenders as a condition of restoring driving privileges.

How a typical Connecticut DUI case unfolds

Connecticut OUI under § 14-227a triggers both criminal prosecution and DMV administrative per se suspension. Alcohol Education Program diversion may be available for eligible first offenders.

Case law: DUI penalties in Connecticut

Ricky A. McCoy v. Commissioner of Public Safety

Ricky A. McCoy v. Commissioner of Public Safety, 300 Conn. 144 (2011)

…tely six years after the legislature decided to criminalize driving under the influence in § 14-227a. Because the Penal Code did not exist at the time the legislature adopted § 14-227a, its placement within the motor vehicle statutes has no impact on determining legislative intent. A review of the motor vehicle chapter reveals other statutes that, like § 14-227a, provide for a…

Ricky A. McCoy v. Commissioner of Public Safety is worth reading on Connecticut DUI penalties because the court put the point in its own words: "Because the Penal Code did not exist at the time the legislature adopted § 14-227a, its placement within the motor vehicle statutes has no impact on determining legislative intent." Use that passage as the starting point, then read the facts that precede it.

State of Connecticut v. John Towry

State of Connecticut v. John Towry, 26 Conn. Super. Ct. 35 (1965)

…deal with the taking of blood from a defendant charged with driving under the influence of intoxicating liquor and with the admissibility in evidence of the amount of alcohol in the defendant’s blood at the time of the alleged offense. Sections 14-227a and 14-227b were enacted in 1963 as part of Public Act No. 616, entitled “An Act concerning Implied Consent to Tests for Intoxi…

State of Connecticut v. John Towry is worth reading on Connecticut DUI penalties because the court put the point in its own words: "Sections 14-227a and 14-227b were enacted in 1963 as part of Public Act No." Use that passage as the starting point, then read the facts that precede it.

State v. King

State v. King, 346 Conn. 238 (2023)

…efendant’s two prior Florida convictions under that state’s driving under the influence statute (§ 316.193 (1)). In enhancing the sentence, the trial court determined that the elements of the Florida statute were ‘‘substantially the same’’ as the elements of § 14-227a (a) for purposes of § 14-227a (g). The Appellate Court upheld the judgment of conviction, and the defendant, on…

Practitioners open State v. King when Connecticut DUI penalties turns on the distinction in this sentence: "Florida convictions under that state’s driving under the influence statute (§ 316.193 (1)). In enhancing the sentence, the trial court determined that the elements of the Florida statute were ‘‘substantially the same’’ as the elements of § 14-227a (a) for purposes of § 14-227a (g)." Do not lift it out of the facts the court was deciding.

Helena Zadroga v. Commissioner of Motor Vehicles

Helena Zadroga v. Commissioner of Motor Vehicles, 42 Conn. Super. Ct. 1 (1991)

…tor’s blood, breath or urine if that person is arrested for driving under the influence of intoxicating liquor or for certain other enumerated crimes. If the person arrested submits to the required test and the results of that test indicate that the ratio of alcohol in the person’s blood was more than ten hundredths of 1 percent of alcohol by weight at the time of the offense,…

Connecticut opinions such as Helena Zadroga v. Commissioner of Motor Vehicles are cited where DUI penalties is disputed. The court stated: "tor’s blood, breath or urine if that person is arrested for driving under the influence of intoxicating liquor or for certain other enumerated crimes. If the person arrested submits to the required test and the results of that test indicate that the ratio of alcohol in the person" That is the language to brief; the rest of the decision supplies the procedural posture.

State of Connecticut v. James LeRoy

State of Connecticut v. James LeRoy, 16 Conn. App. 472 (1988)

…prejudicial without the basis foundation as required under driving under the influence. I can’t believe that a person who’s driving under the influence, a less crime, is afforded more rights than a person charged with a class D felony. It seems inherently— “The Court: It is fair to say, Mr. Austin, your objection is for the failure of the state to comply with the requirements…

Practitioners open State of Connecticut v. James LeRoy when Connecticut DUI penalties turns on the distinction in this sentence: "I can’t believe that a person who’s driving under the influence, a less crime, is afforded more rights than a person charged with a class D felony. It seems inherently— “The Court: It is fair to say, Mr." Do not lift it out of the facts the court was deciding.

STATE OF CONNECTICUT v. JOSEPH PETRUZZELLI

STATE OF CONNECTICUT v. JOSEPH PETRUZZELLI, 45 Conn. App. 804 (1997)

…ause to arrest the defendant at the scene for driving while intoxicated *808but, on the basis of their observations, the trained medical personnel who came to the scene deemed it advisable, necessary and prudent to have the defendant transported to a hospital for a more complete medical diagnosis.3 For the police to have done otherwise would have been in dereliction of their du…

Connecticut opinions such as STATE OF CONNECTICUT v. JOSEPH PETRUZZELLI are cited where DUI penalties is disputed. The court stated: "ause to arrest the defendant at the scene for driving while intoxicated *808but, on the basis of their observations, the trained medical personnel who came to the scene deemed it advisable, necessary and prudent to have the defendant transported to a hospital for a more complete" 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
Lookback period: Prior convictions within 10 years enhance penalties for subsequent operating-under-the-influence offenses.
First-offense range: First-offense OUI is typically a misdemeanor with fines, possible jail (often suspended with probation), license suspension, and ignition-interlock requirements.
Felony threshold: A third OUI within 10 years is a felony; OUI causing serious injury or death can also be charged as a felony.
Ignition interlock: Ignition interlock is mandatory for most OUI offenders as a condition of restoring driving privileges.
Primary authority: Conn. Gen. Stat. § 14-227a.

Blood alcohol limits in Connecticut

0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21

Frequently asked questions

What is the legal BAC limit in Connecticut?