Delaware DUI Laws: Penalties, BAC Limit & License (2026)

In Delaware the offense is called driving under the influence (DUI), and Title 21, Section 4177 of the Delaware Code makes it unlawful to drive with an alcohol concentration of 0.08 or more, or while under the influence of alcohol or drugs. A first DUI is a misdemeanor punishable by a fine of $500 to $1,500, up to 12 months in jail, a license revocation, and a mandatory ignition interlock device.

This guide is part of our DUI Laws by State series.

What counts as a DUI in Delaware

Delaware's core DUI statute, Title 21, Section 4177, makes it unlawful to drive a vehicle while under the influence of alcohol or drugs, or with an alcohol concentration of 0.08 or more within four hours of driving. The four-hour rule is unusual: the State can use a test taken up to four hours after driving and relate it back, so a driver does not avoid the per se charge simply because the test came later. A driver can also be convicted under the impairment prong below 0.08 if alcohol or drugs affected the ability to drive safely. Commercial drivers face a 0.04 limit under Section 4177M, a figure that does not appear in Section 4177 itself. Drivers under 21 are covered by Section 4177L, which works differently from a per se limit: it makes it unlawful to drive while consuming or after having consumed alcoholic liquor, and an alcohol concentration of 0.02 or more is per se evidence that the driver had consumed alcohol rather than an element of the offense. A first violation of Section 4177L carries a 2-month license revocation, or a $200 fine if the driver has no license, not the Section 4177 penalty ladder. The 0.08 figure is the federal benchmark adopted by every state except Utah, which sets its limit at 0.05, as reflected by the National Highway Traffic Safety Administration.

First-offense DUI penalties in Delaware (jail, fines, suspension)

A first DUI under Section 4177 is a misdemeanor. Under Section 4177(d)(1), the penalty is a fine of not less than $500 nor more than $1,500, or imprisonment of not more than 12 months, or both, and any period of imprisonment may be suspended. Most first offenders avoid jail through suspended time and probation, but the conviction still triggers a license revocation handled by the Delaware DMV and a mandatory ignition interlock term. The court also orders an alcohol evaluation and a course of instruction or rehabilitation. Eligible first offenders may instead elect the First Offender Election under Section 4177B, a one-time diversion that requires completion of an evaluation and program in lieu of a trial, available only if the BAC was under 0.15, no injury occurred, and the driver had a valid license.

Watch out: The DMV revocation and the criminal court case are two separate proceedings. You can resolve the criminal case and still lose your license through the DMV, and you generally must request a DMV hearing within 15 days of the arrest notice to contest the administrative revocation.

Ignition interlock requirements in Delaware

Delaware requires an ignition interlock device (IID) for every DUI offender, including first offenders, under Section 4177G and the statewide IID program that became mandatory on February 1, 2015. After serving a minimum mandatory period of revocation, a first offender installs the device to obtain an IID-restricted license and resume driving. Under Section 4177C, a driver who takes the First Offender Election may apply immediately, while a first offender sentenced under Section 4177 must serve at least 30 days of the revocation if the alcohol concentration was below .15, or at least 45 days if it was .15 or more. The Delaware DMV's DUI FAQ still describes a flat 45-day wait before installation, but the statute sets the shorter period for the lower-BAC case. The device requires a breath sample before the engine starts and at random intervals while driving, and it logs every reading for the DMV. The required IID term scales up for repeat offenders. Delaware's all-offender approach means there is no low-BAC exception, so a driver convicted at exactly 0.08 still installs the device.

License revocation and the administrative process in Delaware

Delaware runs two tracks against the driving privilege at the same time. The administrative revocation is an immediate DMV action based on the arrest, independent of the criminal court outcome, as the Delaware DMV explains. Under Title 21, Section 2742, this revocation follows from the officer's certification of probable cause plus the DUI arrest itself, not from a particular test reading: a first offender loses the license for 3 months, a second offender for 1 year, and a driver with more than two offenses for 18 months. The arresting officer serves a notice of revocation that also acts as a temporary permit, and the revocation takes effect unless the driver requests a hearing within 15 days. A conviction then carries its own, longer revocation. Under Section 4177A(a)(1), a first DUI conviction revokes the license for 12 months, or 18 months if the alcohol concentration was .15 to .199, or 24 months if it was .20 or more or the driver refused a chemical test. That is why the Delaware DMV describes a first offense as a 12 to 24 month revocation even though the number on the arrest notice is 3 months. To reinstate, a driver must serve the revocation, complete the required course, install the IID, and pay reinstatement fees.

Repeat offenses and the Delaware look-back period

Delaware counts a prior DUI within a 10-year window to enhance a second offense under Section 4177(d)(2), so a second conviction within 10 years carries higher mandatory fines, jail exposure, and a longer revocation. For third and later offenses, the enhancement is even broader: the statute counts prior DUI convictions regardless of how long ago they occurred, so an old conviction can still elevate a new charge. The felony threshold sits at the third offense, which is a Class G felony under Section 4177(d)(3), and fourth, fifth, and later offenses climb to higher felony classes with mandatory prison time. A DUI that causes serious injury or death can be charged as a felony, such as vehicular assault or vehicular homicide, regardless of offense number.

Watch out: Refusing a chemical test does not avoid a revocation and usually makes it worse. A first refusal results in a 12-month revocation under Section 2742, far longer than the 3-month revocation that follows an arrest without a refusal, and the refusal can be used against you in court.

Refusing a breath or blood test in Delaware

Delaware's implied-consent law means that by driving in the state, you have agreed to submit to a chemical test of blood, breath, or urine if lawfully arrested for DUI. According to Title 21, Section 2742, a first refusal results in a 12-month license revocation, a second in 18 months, and a third or subsequent in 24 months. These refusal revocations are administrative and apply on top of any criminal penalties. Because the 12-month refusal revocation is four times the 3-month revocation that follows an arrest without a refusal, refusing rarely helps and often hurts. The driver may contest the revocation at a DMV hearing requested within 15 days of the notice, but missing that deadline generally forfeits the chance to fight it.

Can you expunge or seal a DUI in Delaware

Delaware does not allow DUI convictions to be expunged. The state's expungement statute, Title 11, Chapter 43, Subchapter VII, excludes offenses under Title 21, and because DUI is codified in Title 21 (Section 4177), a DUI is categorically barred from both mandatory and discretionary expungement. The practical workaround is the First Offender Election under Section 4177B: an eligible first offender who completes the program in lieu of trial avoids a conviction in the first place, which keeps a DUI off the criminal record. That election is a one-time option with strict eligibility, requiring a BAC under 0.15, no injury, no prior offense, and a valid license. A dismissal or an acquittal does not change that. Section 4374(i)(1) provides that the law-enforcement agency records and the court records relating to any charge under Title 21 may not be expunged unless the charge is one of the three enumerated in Section 4374(i)(2), namely Sections 2810, 4175, and 4176A, and Section 4372(f)(2) states the same exclusion. Because the bar runs on the charge rather than on the conviction, a dismissed DUI charge stays outside the expungement statute.

What to do after a DUI arrest in Delaware

A Delaware DUI generates two cases at once: a criminal case in court and an administrative license case at the DMV. The deadlines are short, so a common first step is to request a DMV hearing within 15 days of the arrest notice, because missing that window generally means the revocation takes effect automatically. The criminal case proceeds on its own schedule through arraignment, case review, and resolution. General information cannot tell you how your case will come out, since the outcome depends on the specific facts, the evidence, and your record. Whether the First Offender Election is open turns on those facts too, so have a Delaware DUI lawyer review it and the 15-day DMV hearing request in a free consultation (attorney advertising). Keep the arrest paperwork, the notice of revocation, and any test results in a safe place.

More Delaware Laws

• Delaware Expungement Laws
• Delaware Warrant Search

Frequently Asked Questions

What is the BAC limit in Delaware?

The per se limit is 0.08 alcohol concentration for drivers 21 and older under Title 21 Section 4177, measured within four hours of driving. The 0.04 limit for commercial drivers is set separately by Section 4177M, and Section 4177L bars a driver under 21 from driving after consuming alcoholic liquor, treating 0.02 or more as evidence of that consumption.

How long do you lose your license for a first DUI in Delaware?

There are two separate revocations. On a first DUI arrest the DMV revokes the license for 3 months under Title 21 Section 2742, or 12 months if you refused the chemical test. A first DUI conviction then carries a revocation of 12 months under Section 4177A(a)(1), rising to 18 months if the alcohol concentration was .15 to .199 and 24 months if it was .20 or more or you refused testing.

Is a first DUI a felony in Delaware?

No. A first DUI is a misdemeanor under Section 4177. A DUI becomes a Class G felony on the third offense, and fourth and later offenses are higher-class felonies. A DUI causing serious injury or death can be a felony at any offense level.

Do you need an interlock for a first DUI in Delaware?

Yes. Delaware requires an ignition interlock device for every DUI offender, including first offenders, regardless of BAC, under Section 4177G and the statewide IID program effective February 1, 2015. The device is installed to obtain an IID-restricted license.

What happens if you refuse a breathalyzer in Delaware?

Under implied consent, refusing the chemical test triggers a 12-month license revocation on a first offense under Title 21 Section 2742, far longer than the 3-month revocation that follows an arrest without a refusal. The refusal can also be used as evidence in court.

How long does a DUI stay on your record in Delaware?

A DUI counts as a prior for 10 years for second-offense enhancement, and for third and later offenses it counts regardless of age. The conviction itself stays on the criminal record permanently because Delaware does not allow DUI convictions to be expunged.

Can you get a DUI expunged in Delaware?

No. DUI convictions are excluded from expungement because they fall under Title 21, which the expungement statute in Title 11 bars. The bar in Section 4374(i)(1) runs on the charge, so even a dismissed DUI charge is not eligible. An eligible first offender can avoid a conviction in the first place through the First Offender Election under Section 4177B.

What is the look-back period for DUI in Delaware?

Delaware uses a 10-year look-back period to enhance a second offense under Section 4177(d)(2). For third and later offenses, the statute counts prior DUI convictions regardless of how long ago they occurred.