DUI Laws in Delaware: Penalties, BAC Limits & License Suspension

In Delaware, drunk driving is prosecuted as Driving Under the Influence (DUI) under Delaware Code Title 21, §4177. The standard per se limit is a blood alcohol concentration (BAC) of 0.08% (the same limit used nationwide). If you were arrested, the clock is already running: the officer takes your physical license on the spot and hands you a paper temporary license — and you have only 15 days to request a hearing with the Delaware Division of Motor Vehicles (DMV) to fight the automatic suspension. Miss that window and the suspension takes effect whether or not you are ever convicted. Everything below explains why that deadline matters and what else is at stake.

What Delaware calls this offense

Delaware law titles the offense "driving a vehicle while under the influence or with a prohibited alcohol or drug content," commonly shortened to DUI. It is codified at Title 21, §4177 of the Delaware Code. A separate provision — §4177L, "Driving by persons under 21 after alcohol consumption" — is Delaware's zero-tolerance law for underage drivers. Which section you are charged under depends on your age and the circumstances.

Delaware's BAC limits

• 0.08% or higher — the general per se limit for drivers 21 and over under §4177. At or above this level, the state does not need additional proof of impairment; the number itself is the violation.
• 0.04% or higher — the limit for anyone operating a commercial motor vehicle (CDL holders), consistent with federal commercial-licensing rules.
• 0.02% or higher — Delaware's zero-tolerance threshold for drivers under 21, charged under §4177L. Because the drinking age is 21 nationwide, this is meant to catch any detectable drinking-and-driving by someone under 21, not just heavy impairment.
• 0.15% or higher — Delaware treats this as an aggravated/high-BAC case for license-revocation purposes. A BAC of 0.15% up to 0.199% extends the license revocation to 18 months, and 0.20% or higher extends it to 24 months, compared with the standard 12-month revocation for a first offense below that threshold.

These BAC numbers can change with legislative amendments, so if you are relying on this for a pending case, confirm the current text of §4177 and §4177L directly or with a Delaware criminal defense attorney.

Implied consent and refusing a chemical test

By driving in Delaware, you are considered to have already consented to a breath, blood, or urine test if an officer has reasonable grounds to believe you were driving under the influence. Refusing that test does not avoid consequences — it triggers its own automatic license revocation, separate from and in addition to any DUI charge, and the fact that you refused can also be used as evidence against you in the criminal case.

Under Delaware's implied-consent law, the revocation for refusal escalates with each prior violation:

• No previous violation: 1-year (12-month) license revocation for drivers 21 and older; 2 months for an under-21 driver handled under the §4177L zero-tolerance provision.
• One previous violation: 18-month revocation (6 months for underage cases).
• Two or more previous violations: 24-month revocation (12 months for underage cases).

Refusing a test is often assumed to be a way to "beat" a DUI. It is not — you can still be charged with DUI based on officer observations, field sobriety tests, and other evidence, and you will be facing the refusal revocation on top of it.

Administrative license suspension: the deadline that can't wait

This is the part people miss because it happens fast and separately from the criminal court process. Whether you failed a chemical test or refused one, the arresting officer takes your Delaware license and issues a temporary paper license, and the state moves to revoke your driving privilege administratively.

Within 15 days of the notice, you (or your attorney) must submit a written request for a hearing to contest the revocation before it takes effect. The request goes to the Secretary (through the Delaware Division of Motor Vehicles), and the hearing is held before the Secretary or the Secretary's designee — a process entirely separate from, and faster than, your criminal DUI case in court. If a written request does not reach the DMV within that 15-day window, the revocation is imposed automatically, regardless of how your criminal charge is eventually resolved.

If you were just arrested: mark the 15-day deadline right now and contact the DMV or a Delaware defense attorney immediately — this is not something to leave for later.

First-offense penalties

For a first DUI conviction in Delaware, which is a misdemeanor, §4177 generally provides:

• Fine and jail exposure: the statute sets a fine of not less than $500 and not more than $1,500, and imprisonment of up to 12 months — and it allows the court to suspend the period of imprisonment, which commonly happens for a genuine first-time offender. Your actual exposure depends heavily on the specifics (BAC level, whether anyone was hurt, prior record), and these figures can be amended, so confirm the current terms of §4177 with the court or a Delaware defense attorney before assuming what you face.
• License revocation: typically 12 months, extended to 18 months (BAC 0.15% to 0.199%) or 24 months (BAC 0.20% or higher, or a test refusal), as described above.
• Ignition interlock device (IID): Delaware runs an Ignition Interlock Device Program (§4177G), and installing a functioning interlock is generally required to drive during or after the revocation period following a DUI conviction. Ask the court or DMV exactly how it applies in your case.
• Alcohol evaluation and treatment: Delaware courts typically require an alcohol/drug evaluation and completion of an education or treatment program as part of sentencing.

Delaware also offers a first-offender program under §4177B that can allow some eligible first-time offenders to resolve the case through probation and treatment conditions in lieu of trial. Eligibility rules are specific and not automatic, so ask the court or a defense attorney whether you qualify.

Lookback period: how long a prior DUI counts against you

Delaware uses a 10-year lookback to decide whether a new DUI counts as a second offense: a prior offense within the last 10 years enhances the new charge to second-offense penalties, with a longer license revocation and higher mandatory minimums.

Once you reach a third offense, Delaware drops that time limit. For third-offense (and later) sentencing, the statute counts all prior DUI convictions regardless of how long ago they occurred — there is no washout period at that stage. A DUI from decades earlier can still count toward making a new charge a felony.

Felony DUI in Delaware

A DUI becomes a felony in Delaware at the third offense (counting all priors, with no time limit, as explained above). A third offense is a Class G felony carrying mandatory minimum incarceration, and a fourth offense escalates to a Class E felony with greater penalties, in addition to fines, extended license revocation, and mandatory ignition interlock. Because these classifications and minimum-sentence figures can be amended, confirm the current felony threshold and minimum sentence under §4177 with the court or a defense attorney rather than relying on a remembered number.

Separately, causing serious injury or death while driving impaired can expose you to additional, more serious charges beyond the DUI statute itself (such as vehicular assault or homicide-related offenses), which carry their own penalty structures. If that applies to your situation, you need an attorney immediately — this is well beyond the scope of a general overview.

What to do after a DUI arrest in Delaware

1. Write down the date of your arrest and count 15 days forward. That is your deadline to submit a written request for a DMV hearing to contest the license revocation — before you do anything else, confirm this deadline and how to submit the request.
2. Contact the Delaware Division of Motor Vehicles to confirm your temporary license's exact expiration date and the current process for requesting a hearing, since procedures can be updated.
3. Talk to a Delaware criminal defense attorney as soon as possible, ideally before the 15-day window closes, since the attorney can request the hearing on your behalf and start building your defense in the separate criminal case at the same time.
4. Do not assume the criminal case and the license revocation are the same process. They run on different timelines, and missing the DMV deadline forfeits your right to fight the revocation even if you are later found not guilty.
5. Ask about eligibility for the first-offender program under §4177B if this is genuinely your first offense, and ask what an alcohol evaluation or treatment requirement will involve in your case.
6. Keep every piece of paperwork the officer gave you, including the temporary license and any notice of revocation, and bring it to your attorney or the DMV.

This article is general legal information about Delaware law, not legal advice for your specific situation — confirm current statutes and deadlines with the Delaware DMV, the courts, or a licensed Delaware attorney.