Delaware DUI Laws

The per se limit is 0.08% (21 Del. C. § 4177(a)(4)). The offense also covers impairment by alcohol, drugs, or a combination regardless of BAC, AND a separate any-amount per-se prohibition on illicit or recreational drugs under (a)(6). The under-21 limit is 0.02% (§ 4177L).

A first offense (21 Del. C. § 4177(d)(1)) carries a $500–$1,500 fine and/or up to 12 months in jail (suspendable). License revocation is 12 months standard, 18 months at BAC .15–<.20, or 24 months at BAC .20+ or on refusal (§ 4177A(a)(1)). IID is mandatory (§ 4177(e)); the IID period before full reinstatement is 12 months (BAC < .15), 17 months (.15–<.20), or 23 months (.20+) under § 4177C(d)(4). A first offender with no prior, no injury accident, BAC < .15, and no child passenger may be eligible for the § 4177B first-offender election (probation, 4-month IID, no guilty judgment).

A second offense within 10 years (21 Del. C. § 4177(d)(2)) carries a $750–$2,500 fine and 60 days to 18 months in jail, with the 60-day minimum non-suspendable except via Veterans' Treatment Court or the CCP DUI Treatment Program. License revocation is 18 months standard, 24 months at BAC .15–<.20, or 30 months at BAC .20+ or on refusal (§ 4177A(a)(2)). IID is mandatory; the IID period before full reinstatement is 16/22/28 months (BAC-tiered) under § 4177C(d)(4).

A THIRD offense makes it a felony — and the felony ladder escalates by lifetime count. A 3rd offense is a class G felony (1–2 years, first 3 months non-suspendable at Level V); 4th is class E (2–5 years); 5th is class E (3–5 years); 6th is class D (4–8 years); 7th or subsequent is class C (5–15 years) under 21 Del. C. § 4177(d)(3)–(7). Unlike the 10-year window that governs the first→second misdemeanor escalation, § 4177B(e)(2)b imposes NO time limit on the felony tiers — all prior qualifying offenses ever count.

License revocation under 21 Del. C. § 4177A is BAC-tiered for the first three offenses: a first offense is 12 months (18 at .15–<.20, 24 at .20+/refusal); a second is 18 months (24/30); a third is 24 months (30/36); a fourth or subsequent is a flat 60 months regardless of BAC. A separate administrative revocation under § 2742 may run alongside. The person may drive during the revocation period ONLY by installing an IID and obtaining an IID license under § 4177C.

Yes — IID is mandatory at every tier under 21 Del. C. § 4177(e). The person may drive during the revocation period only by installing an IID on each vehicle they own or operate and obtaining an IID license under § 4177C. The IID period before full reinstatement scales with offense count AND BAC: 12/17/23 months (1st offense, BAC-tiered), 16/22/28 months (2nd), 21/27/33 months (3rd), or 54 months (4th+) under § 4177C(d)(4). A first-offender-election participant under § 4177B needs only 4 months. Violating the IID restriction at the time of a new offense carries an additional $2,000 fine and 60 days in jail (§ 4177(e)).

Refusing a lawfully requested test is NOT a separate crime — it is an administrative matter under 21 Del. C. § 2742. The DMV imposes a revocation of 1 year (no prior within 5 years), 18 months (one prior), or 24 months (two or more priors). Refusal also re-routes the CONVICTION-track revocation under § 4177A to the .20-tier duration (24/30/36 months for first/second/third offense). The administrative and conviction-track revocations run alongside each other. A person involved in a fatal or serious-injury accident may be tested without consent when the officer proceeds without invoking the implied-consent warning (§ 2742(a)). The refusal may also be used as evidence at trial.

A driver under 21 is subject to a separate zero-tolerance offense under 21 Del. C. § 4177L at a measured 0.02% BAC — not an any-amount rule. The penalty is a 2-month license revocation for a first offense (6–12 months for each subsequent), or a $200 fine ($400–$1,000 subsequent) if the person has no license, plus a mandatory drug/alcohol evaluation and education program. A driver under 21 at 0.08% or above is also charged under the adult § 4177 statute.

It depends on which tier the current offense falls into. For a SECOND offense, the second must occur within 10 years of a prior to be sentenced under § 4177(d)(2) (21 Del. C. § 4177B(e)(2)a). For a THIRD or subsequent (felony-tier) offense, there is NO time limitation — § 4177B(e)(2)b provides that all prior qualifying offenses ever count. The prior-conviction definition is broad: it includes a § 4177 or § 4175(c) conviction, a substantially similar out-of-state/local/federal/military conviction, a conviction for a criminal statute encompassing death or injury by driving where DUI was an element, AND participation in a first-offender diversion program (which counts as a prior even without a guilty plea).

A DUI committed while a person under 17 is on or within the vehicle triggers an enhanced penalty under 21 Del. C. § 4177(d)(10): an additional $500–$1,500 fine and 40 hours of community service for a first such offense, or $750–$2,500 and 80 hours for each subsequent. This stacks on top of the underlying § 4177 penalty. It also disqualifies the person from the § 4177B first-offender election.

Yes — 21 Del. C. § 4177B allows a first offender to elect probation in lieu of trial (no judgment of guilt entered). To qualify, the person must have no prior qualifying offense, fewer than 3 moving violations in 2 years, no accident injury, BAC below .15, a valid license, and no child-passenger enhancement. The revocation period is 1 year, but the person may obtain an IID license under § 4177C after surrendering all licenses and installing an IID; the IID period before full reinstatement is only 4 months. The election requires paying prosecution costs ($250) and waiving the right to a § 2742 administrative hearing. Successful completion discharges the proceedings; violation of probation results in adjudication of guilt under § 4177.

Two BAC tiers modulate the license and IID consequences — but they do NOT create a separate charge. A BAC of .15 to less than .20 extends the license revocation under § 4177A (e.g., 12→18 months on a first offense) and the IID reinstatement period under § 4177C(d)(4) (12→17 months). A BAC of .20 or greater extends them further (24 months revocation, 23 months IID on a first offense). Refusal triggers the same .20-tier revocation periods. These are sentencing/reinstatement breakpoints, not separate per-se offenses.