Start with Iowa Code § 321J.2. In Iowa, BAC limits: 0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21. A first offense: First-offense OWI is typically a serious misdemeanor with fines, possible jail, license revocation, substance-abuse evaluation, and temporary restricted license / interlock conditions. Felony threshold: A third OWI within 12 years is a class D felony; OWI causing serious injury or death can also be a felony. That is the question this guide answers for DUI penalties. Lookback: Prior OWI convictions within 12 years enhance penalties.. Ignition interlock: Ignition interlock is commonly required for temporary restricted licenses after OWI.
Blood alcohol limits in Iowa
0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21
Lookback window for prior offenses
Prior OWI convictions within 12 years enhance penalties.
How the Iowa rule applies
Apply the Iowa authorities in order. The facts are simplified so the statute and the standard are visible.
A driver in Iowa 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 OWI is typically a serious misdemeanor with fines, possible jail, license revocation, substance-abuse evaluation, and temporary restricted license / interlock conditions.
- Ask when the charge becomes a felony: A third OWI within 12 years is a class D felony; OWI causing serious injury or death can also be a felony. Lookback: Prior OWI convictions within 12 years enhance penalties.
- Interlock: Ignition interlock is commonly required for temporary restricted licenses after OWI.
Iowa OWI under § 321J.2 proceeds in district court with parallel DOT administrative revocation. Defense reviews the stop and DataMaster record.
First-offense penalties
First-offense OWI is typically a serious misdemeanor with fines, possible jail, license revocation, substance-abuse evaluation, and temporary restricted license / interlock conditions.
When a Iowa DUI becomes a felony
A third OWI within 12 years is a class D felony; OWI causing serious injury or death can also be a felony.
Ignition interlock and license consequences
Ignition interlock is commonly required for temporary restricted licenses after OWI.
How a typical Iowa DUI case unfolds
Iowa OWI under § 321J.2 proceeds in district court with parallel DOT administrative revocation. Defense reviews the stop and DataMaster record.
Related Iowa guides
- How to file for divorce in Iowa
- Child custody and parenting time in Iowa
- Security deposit return in Iowa
Case law: DUI penalties in Iowa
STATE of Iowa, Appellee, v. Carrie McIVER, Appellant — Wiggins, J., concurring in part and dissenting in part
…making sure that if the officer suspected the defendant was driving under the influence of drugs, the officer must arrange to administer a blood or urine test to ensure the state and the defendant would have the necessary evidence to litigate the prescription-drug defense, if raised. In other words, the purpose of the amendment, as evidenced by the legislative history, requires…
Practitioners open STATE of Iowa, Appellee, v. Carrie McIVER, Appellant — Wiggins, J., concurring in part and dissenting in part when Iowa DUI penalties turns on the distinction in this sentence: "making sure that if the officer suspected the defendant was driving under the influence of drugs, the officer must arrange to administer a blood or urine test to ensure the state and the defendant would have the necessary evidence to litigate the prescription-drug defense, if rai" Do not lift it out of the facts the court was deciding.
STATE of Iowa, Appellee, v. Jonathan Q. ADAMS, Appellant — Waterman, J., concurring
…does not require any erratic or negligent driving. Because driving under the influence of an intoxicant is malum prohibitum it is impossible to separate the intoxication from the driving or the driving from the intoxication.... ... The statute does not include as an element of the crime a direct causal connection between the fact of defendant’s intoxication, conceptualized as…
Iowa opinions such as STATE of Iowa, Appellee, v. Jonathan Q. ADAMS, Appellant — Waterman, J., concurring are cited where DUI penalties is disputed. The court stated: "Because driving under the influence of an intoxicant is malum prohibitum it is impossible to separate the intoxication from the driving or the driving from the intoxication.... ..." That is the language to brief; the rest of the decision supplies the procedural posture.
Philip Charles HOFFMAN, Appellee, v. the IOWA DEPARTMENT OF TRANSPORTATION, Appellant — Mason, J., concurring
…he implied-consent law is to coerce the driver suspected of driving under the influence into ‘consenting’ to chemical testing, thereby allowing scientific evidence of his blood-alcohol content to be used against him in a subsequent prosecution for that offense. * [citing authority]. The license revocation proceeding thus becomes an arm of the prosecutor in his attempt to ga…
Practitioners open Philip Charles HOFFMAN, Appellee, v. the IOWA DEPARTMENT OF TRANSPORTATION, Appellant — Mason, J., concurring when Iowa DUI penalties turns on the distinction in this sentence: "he implied-consent law is to coerce the driver suspected of driving under the influence into ‘consenting’ to chemical testing, thereby allowing scientific evidence of his blood-alcohol content to be used against him in a subsequent prosecution for that offense. * [citing auth" Do not lift it out of the facts the court was deciding.
STATE of Iowa, Appellee, v. Daryl Lloyd BRATTHAUER, Appellant
STATE of Iowa, Appellee, v. Daryl Lloyd BRATTHAUER, Appellant, 1984 Iowa Sup. LEXIS 1237 (1984)
…between the blood alcohol level in a defendant’s blood and driving under the influence. Section 321.281(8) makes evidence of ten hundredths or more of one percent' by weight of alcohol in a defendant’s blood “presumptive evidence that the defendant was under the influence of an alcoholic beverage.” In rejecting a due process attack on this rebuttable presumption in *777 State…
Practitioners open STATE of Iowa, Appellee, v. Daryl Lloyd BRATTHAUER, Appellant when Iowa DUI penalties turns on the distinction in this sentence: "Section 321.281(8) makes evidence of ten hundredths or more of one percent' by weight of alcohol in a defendant’s blood “presumptive evidence that the defendant was under the influence of an alcoholic beverage." Do not lift it out of the facts the court was deciding.
STATE of Iowa, Appellant, v. Richard Lee PRICE, Appellee
STATE of Iowa, Appellant, v. Richard Lee PRICE, Appellee, 2005 Iowa Sup. LEXIS 20 (2005)
…994) (holding intoxilyzer test results in a prosecution for driving under the influence were “competent evidence, which the trier of fact may consider in the context of other evidence”); State v. Kimball, 361 N.W.2d 601, 603 (N.D.1985) (concluding 0.11 BAC was relevant to prove defendant operated a vehicle while under the influence of alcohol); State v. Comstock, 145 Vt. 503, 4…
Iowa opinions such as STATE of Iowa, Appellant, v. Richard Lee PRICE, Appellee are cited where DUI penalties is disputed. The court stated: "State v. Kimball, 361 N.W.2d 601, 603 (N.D.1985) (concluding 0.11 BAC was relevant to prove defendant operated a vehicle while under the influence of alcohol); State v. Comstock, 145 Vt." That is the language to brief; the rest of the decision supplies the procedural posture.
STATE of Iowa, Appellant, v. Justin Joseph HUTTON, Appellee
STATE of Iowa, Appellant, v. Justin Joseph HUTTON, Appellee, 2011 Iowa Sup. LEXIS 23 (2011)
…le, contending we equated “failing” a breath *904 test with driving under the influence of alcohol. Although we may consider former and subsequent versions of a statute to ascertain the legislature’s intent, we only do so when the statutory language is ambiguous. State v. Guzman-Juarez, 591 N.W.2d 1, 3 (Iowa 1999); see also State v. Spencer, 737 N.W.2d 124, 129 (Iowa 2007). A s…
Practitioners open STATE of Iowa, Appellant, v. Justin Joseph HUTTON, Appellee when Iowa DUI penalties turns on the distinction in this sentence: "Although we may consider former and subsequent versions of a statute to ascertain the legislature’s intent, we only do so when the statutory language is ambiguous. State v. Guzman-Juarez, 591 N.W.2d 1, 3 (Iowa 1999); see also State v. Spencer, 737 N.W.2d 124, 129 (Iowa 2007)." Do not lift it out of the facts the court was deciding.
Key takeaways
- BAC limits: 0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21
- Lookback period: Prior OWI convictions within 12 years enhance penalties.
- First-offense range: First-offense OWI is typically a serious misdemeanor with fines, possible jail, license revocation, substance-abuse evaluation, and temporary restricted license / interlock conditions.
- Felony threshold: A third OWI within 12 years is a class D felony; OWI causing serious injury or death can also be a felony.
- Ignition interlock: Ignition interlock is commonly required for temporary restricted licenses after OWI.
- Primary authority: Iowa Code § 321J.2.
Frequently asked questions
What is the legal BAC limit in Iowa?
0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21
Is a first DUI a felony in Iowa?
A third OWI within 12 years is a class D felony; OWI causing serious injury or death can also be a felony.
Will I need an ignition interlock device?
Ignition interlock is commonly required for temporary restricted licenses after OWI.
This guide covers Iowa 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.