Delaware DUI Laws: BAC Limits, Penalties, and License Revocation

Under Delaware DUI laws, a first conviction brings a fine of $500 to $1,500, up to 12 months of possible jail time, license revocation, and mandatory enrollment in an alcohol education or rehabilitation program. Penalties climb sharply with each subsequent offense and become felony-level at the third conviction. A single arrest also triggers two separate proceedings at once: a criminal case in court and an administrative license revocation through the Division of Motor Vehicles.

Legal BAC Limits in Delaware

It is illegal to drive in Delaware with a blood alcohol concentration of 0.08% or higher.¹ That number is a “per se” threshold: crossing it is enough for a charge whether or not your driving was actually impaired. An officer does not have to prove you swerved or drove badly if a chemical test puts you at or above the limit.

Two categories of drivers face lower limits. Commercial vehicle operators cannot drive with a BAC of 0.04% or higher, and a violation is classified as an unclassified misdemeanor.² Drivers under 21 fall under a near-zero-tolerance rule: a BAC of 0.02% or higher is per se evidence of consumption and triggers a license revocation of at least two months for a first offense.³

First-Offense Penalties

A first DUI conviction carries a fine of $500 to $1,500 and up to 12 months in jail. The entire jail sentence may be suspended at the court’s discretion.⁴ Many first offenders receive probation instead of jail, but a judge can still impose incarceration based on aggravating factors like a crash or a very high BAC.

Before your license can be reinstated, you must complete a state-approved course of instruction or rehabilitation program run through the Division of Substance Abuse and Mental Health.⁵ Successfully completing the Court of Common Pleas DUI Treatment Program satisfies this requirement.

Second-Offense Penalties

A second DUI within ten years of a prior offense brings a fine of $750 to $2,500 and a jail sentence of 60 days to 18 months. The 60-day minimum generally cannot be suspended.⁴ The court may suspend that minimum only in narrow circumstances, such as successful completion of the Superior Court’s Veterans’ Treatment Court or the Court of Common Pleas DUI Treatment Program with at least 30 days of community service.

The ten-year lookback is what matters here. If your prior DUI is more than ten years old, sentencing follows first-offense guidelines. Inside that window, the mandatory jail time makes the second conviction a fundamentally different experience from the first.

Third and Subsequent Offenses: Felony DUI

DUI becomes a felony at the third conviction, and the classification and mandatory prison time step up from there.

Third offense (Class G felony): up to $5,000 in fines and one to two years in prison. The first three months must be served at the highest supervision level without early release or furlough. Up to nine months of the minimum may be suspended if you complete both an abstinence program and a treatment program.
Fourth offense (Class E felony): up to $7,000 in fines and two to five years in prison. The first six months must be served with no early release. Up to 18 months of the minimum may be suspended.
Fifth offense (Class E felony): up to $10,000 in fines and three to five years in prison.
Sixth offense (Class D felony): up to $10,000 in fines and four to eight years in prison.

All tiers sit under the same statute.⁴ A felony conviction stays on background checks for employment, housing, and licensing indefinitely, and federal law restricts firearm ownership for convicted felons.

Administrative License Revocation

Separately from anything a court does, the DMV revokes your license based on the arrest itself. The arresting officer takes your Delaware license on the spot and issues a temporary permit valid for 15 days.⁶ Within that 15-day window, you can file a written request for a DMV hearing. Miss the deadline and the revocation takes effect automatically.

Administrative revocation lengths for a DUI arrest are:

First DUI: three months
Second DUI: one year
Third or subsequent DUI: 18 months

These periods apply based on the arrest alone, before any criminal conviction.⁷ Requesting a hearing stays the revocation until a hearing officer decides, and the hearing must be scheduled within 60 days of your request.

Chemical Testing and Refusal

By driving on Delaware roads, you are treated as having already consented to a breath, blood, or urine test when an officer has probable cause to believe you are impaired. This is Delaware’s implied consent law.⁸ Probable cause can come from erratic driving, the smell of alcohol, slurred speech, or performance on field sobriety exercises. You do not have the right to consult an attorney before deciding whether to test.

Refusing a test triggers its own revocation, wholly separate from any criminal DUI penalty:

First refusal with no prior DUI or refusal within five years: one-year revocation
Second refusal or refusal with a prior DUI/refusal: 18-month revocation
Third or subsequent refusal: 24-month revocation

These apply even if you are never convicted of DUI.⁷ The refusal can also be introduced as evidence in the criminal case, so refusing typically makes both tracks worse rather than better.

Getting Back on the Road: Ignition Interlock

Rather than sit out the full revocation, most drivers can apply for an Ignition Interlock Device license. The device prevents the vehicle from starting if it detects alcohol, and it must be installed on every vehicle you operate regardless of ownership.⁹

When you become eligible depends on your history and BAC:

First offender, BAC below 0.15: after 30 days
First offender, BAC 0.15 or higher: after 45 days
Second offender: after 60 days
Third offender: after 90 days
Fourth or subsequent offender: after six months

You must also be enrolled in or have completed the required education or rehabilitation program before applying.¹⁰ The monthly monitoring and calibration fee is capped at $75 by state regulation.¹¹ Installation and removal fees come on top of that, and the DMV must offer a payment plan and an indigent program for those who cannot afford the costs.

Tampering with, bypassing, disabling, or removing the device extends your program participation, and repeat violations can get you disqualified from the program entirely. If that happens, the device stays on your vehicle, but you lose all driving privileges for the rest of the period.⁹

Drug DUI

Delaware’s DUI statute is not limited to alcohol. It is equally illegal to drive under the influence of any drug, a combination of alcohol and drugs, or with any amount of an illicit or recreational substance in your blood.¹ The definition of “illicit or recreational drug” is broad, covering Schedule I substances, cocaine, amphetamines, methamphetamine, PCP, designer drugs, and inhaled substances used to get high.

Penalties match the alcohol schedule at every tier. Because there is no numeric equivalent to the 0.08% threshold, the mere presence of certain drugs in your blood within four hours of driving is enough to support a charge.

What a DUI Does to a CDL

A DUI conviction hits commercial license holders twice: once under Delaware law and again under federal disqualification rules. A first DUI offense in a commercial vehicle results in a minimum one-year CDL disqualification. A second DUI-related offense in any vehicle brings a lifetime disqualification.¹² These federal disqualifications apply whether the offense happened in a commercial or personal vehicle. The federal commercial BAC limit is 0.04%,¹³ and Delaware mirrors it in state law.²

Costs Beyond the Fine

Court fines are only part of what a DUI costs. Delaware does not require SR-22 filings, which spares you one recurring expense that most states impose. Insurance is a different story: carriers treat a DUI as a major risk factor, and rate increases of 30% or more are common nationwide, usually lasting three to five years.

You should also plan for DMV reinstatement fees, the cost of the alcohol education or rehabilitation program, interlock installation and monthly monitoring (up to $75 per month for monitoring), and legal fees. Private DUI defense typically runs from $1,500 to $25,000, depending on complexity, whether the case goes to trial, and the attorney’s experience.

Travel and Immigration

Canada treats impaired driving as a serious offense under its immigration law, and even a single misdemeanor DUI from the United States can make you inadmissible at the border. Canadian officers have access to U.S. criminal records and can turn you away at land crossings and airports. Options to overcome inadmissibility include Criminal Rehabilitation, available once at least five years have passed since you completed your entire sentence, or a Temporary Resident Permit for individual trips.

Non-citizens in the United States face their own risks. USCIS runs background checks during visa renewals, green card applications, and naturalization. Two or more DUI convictions can trigger removal proceedings and may make you ineligible to renew a visa, adjust status, or naturalize. A drug-related DUI can cause immigration problems on its own, because substance abuse is a separate ground of inadmissibility.

Reinstating Your License

Getting your license back takes more than waiting out the revocation. You must complete the required education or rehabilitation program, pay all DMV reinstatement fees, and satisfactorily complete the interlock program if you participated.¹⁰ If you were disqualified from the interlock program for noncompliance, you have to serve out the full remaining revocation and extension period before reinstatement is possible.

For repeat offenders, the path is longer. Second and subsequent offenders must be enrolled in or have completed the rehabilitation program before applying for an interlock license, and their waiting periods stretch from 60 days to six months or more. Miss a step and the clock resets.

1
Justia. Delaware Code 21-4177 – Driving a Vehicle While Under the Influence or With a Prohibited Alcohol or Drug Content
2
Justia. Delaware Code 21-4177M – Operating a Commercial Motor Vehicle With a Prohibited Blood Alcohol Concentration or While Impaired by Drugs
3
Justia. Delaware Code 21-4177L – Driving by Persons Under the Age of 21 After Consumption of Alcohol; Penalties
4
Delaware Code Online. Delaware Code Title 21 – Rules of the Road
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Justia. Delaware Code 21-4177D – Courses of Instruction; Rehabilitation Programs
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Delaware Code Online. Delaware Code Title 21 – Suspension and Revocation of License for Refusal to Submit to Chemical Test
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Justia. Delaware Code 21-2742 – Revocation; Notice; Hearing
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Justia. Delaware Code 21-2740 – Consent to Submit to Chemical Test; Probable Cause; Test Required
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Justia. Delaware Code 4177G – Ignition Interlock Device Program
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Justia. Delaware Code 21-4177C – Ignition Interlock Licenses; Reinstatement of License
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Delaware Regulations. 2 DE Admin. Code 2223 – Ignition Interlock Device Installation, Removal and Monthly Monitoring and Calibration Fees
12
eCFR. 49 CFR 383.51 – Disqualification of Drivers
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Federal Motor Carrier Safety Administration. Is a Driver Disqualified for Driving a CMV While Off-Duty With a Blood Alcohol Concentration Over 0.04 Percent?