Quick answer: Maryland DUI and DWI laws all live in one statute — Md. Code, Transp. § 21-902. It creates two main alcohol charges: DUI under subsection (a), the more serious offense (you were under the influence, or your BAC was 0.08 or higher “per se”), and DWI under subsection (b), the lesser charge for being impaired to a smaller degree. A different statute — Cts. & Jud. Proc. § 10-307 — decides what your BAC number lets a court presume; it does not pick your charge. And every stop actually starts two cases: a criminal case in District Court and a separate MVA action against your license.
I’m David Waranch, and I’ve handled thousands of Maryland traffic and impaired-driving cases. This page is the framework — what each charge means and how the pieces connect. For the full sentencing numbers, see my Maryland DUI penalties page; for how a defense actually works, start with the Maryland DUI lawyer overview.
Maryland DUI vs. DWI: What § 21-902 Actually Says
Maryland doesn’t have one drunk-driving crime. It has one statute holding several distinct offenses, each with its own burden of proof. That’s why a single stop routinely produces a citation with three or four counts that all sound alike — the State charges every version it might be able to prove and sorts it out later.
The dividing line is the degree of impairment. DUI under § 21-902(a) is the top charge: either you were genuinely under the influence of alcohol, or your test came back at 0.08 or more, which is DUI per se — the number alone. DWI under § 21-902(b) is the lesser charge for being impaired by alcohol to a smaller degree. Two more subsections cover drugs: § 21-902(c) for impairment by a drug or a drug-and-alcohol combination, and § 21-902(d) for a controlled dangerous substance you’re not entitled to use. All of them are criminal misdemeanors under the Maryland Vehicle Law — none is a payable traffic ticket you can settle by mail. For a side-by-side on how the two alcohol charges compare, see DUI vs. DWI in Maryland.
| Charge | Statute | What the State must prove | Max jail (1st) |
|---|---|---|---|
| DUI — under the influence | § 21-902(a)(1)(i) | Substantial impairment by alcohol; no BAC reading required | Up to 1 year |
| DUI per se | § 21-902(a)(1)(ii) | A BAC of 0.08 or more — nothing else | Up to 1 year |
| DWI — impaired by alcohol | § 21-902(b)(1) | A lesser degree of alcohol impairment | Up to 2 months |
| Impaired by drugs or drugs + alcohol | § 21-902(c)(1) | So impaired you cannot drive safely | Up to 2 months |
| Impaired by a controlled substance | § 21-902(d)(1) | Impairment by a CDS you can’t legally use | Up to 1 year |
What Your BAC Number Really Means (§ 10-307)
Here’s where most explanations of Maryland law go wrong. People describe DWI as “the charge you get for a 0.07,” as if the statute assigned charges by BAC bracket. It doesn’t. The brackets live in a completely separate statute, § 10-307, and that statute is a rule of evidence. It doesn’t tell the State what to charge — it tells the court what it may presume from the number:
- 0.05 or less — presumed you were not under the influence and not impaired.
- More than 0.05, under 0.07 — no presumption either way; the number goes to the trier of fact with everything else.
- 0.07 up to 0.08 — prima facie evidence of DWI. Enough, on its own, to support the impaired charge.
- 0.08 or more — under the influence per se. The reading itself is the offense.
- 0.02 or more — prima facie evidence of driving with alcohol in your blood and of violating any alcohol restriction on your license under § 16-113. This is the provision that matters for drivers under 21.
“If at the time of testing a person has an alcohol concentration of 0.08 or more … the person shall be considered under the influence of alcohol per se.” — Cts. & Jud. Proc. § 10-307(g)
Myth: no breath test, no case. False. Section 21-902(a)(1)(i) lets the State convict you of DUI with no BAC reading at all — on the officer’s observations, your driving, the field sobriety tests, and the dashcam or bodycam video. Refusing the breath test removes one piece of the State’s evidence; it does not remove the charge, and the refusal triggers its own license suspension.
Per Se vs. Impairment: Two Roads to the Same Conviction
The per se route and the impairment route are exactly that — two independent ways to reach a conviction. Per se means the State proves a single fact: a valid 0.08-or-higher reading. It doesn’t have to show you drove badly or looked drunk. The impairment route is the opposite: no number is needed, only proof that alcohol affected your ability to drive, built from observations, admissions, and the tests.
Two things follow, and they’re the reverse of what most people assume. A high BAC does not put a DWI plea out of reach — a 0.14 case is routinely resolved as a DWI through negotiation. And a low reading, or no reading, does not make you safe, because the impairment charge doesn’t depend on the machine at all. The presumptions govern what a number proves. They are not the charge.
The drug subsections work the same way, minus the BAC math. Under § 21-902(c) and (d) the question is simply whether a drug — legal or not — left you unable to drive safely. And a valid prescription is not a defense: § 21-902(c)(1)(iv) says being lawfully entitled to use the drug doesn’t excuse it unless you were unaware it would make you incapable of driving. A drowsiness warning on the label makes that argument very hard. More on that in driving under the influence of drugs in Maryland.
Two Cases at Once: Criminal Court and the MVA
The biggest structural surprise in Maryland impaired-driving law is that you’re fighting on two fronts. The criminal case under § 21-902 decides guilt and sentence in District Court. Running alongside it — on its own schedule, under its own rules — is the MVA’s administrative action against your license under Transp. § 16-205.1. This is the “administrative per se” case, and it doesn’t wait for the criminal one. Winning in court does not automatically save your license.
Here’s the sequence that catches people. A 0.08-or-higher result, or a refusal, lets the officer take your card and hand you a paper temporary license good for 45 days. To keep your options open you have to request an MVA hearing within 10 days — a request made later (up to 30 days) still gets you a hearing, but it won’t extend that 45-day window. At the hearing the exposure ranges from a 180-day suspension for a first 0.08–0.15 test up to 270 days for a first refusal and 2 years for a second. The Ignition Interlock Program is the common alternative, and it’s mandatory to keep driving after a 0.15-or-higher result or a refusal. Because the deadline is so short, this is the part of a DUI most worth acting on first — see Maryland license suspension lengths and what to expect at the MVA per se hearing.
Where PBJ and Pleas Fit In
Because DUI and DWI are must-appear charges, there’s always a court date and always a negotiation. The most common favorable outcomes are a plea down from DUI to the lesser DWI, or a probation before judgment (PBJ) under Crim. Proc. § 6-220. A PBJ is not a conviction — no points hit your record — but it isn’t automatic and it isn’t unlimited. Under § 6-220(f)(1), a court may not grant PBJ for a § 21-902 offense if within the preceding 10 years you were convicted of, or already received a PBJ for, a § 21-902 offense. Which option is realistic turns on the facts, the reading, and your history. For the full menu, see DUI plea options and PBJ in Maryland.
Frequently Asked Questions
DUI under Transp. section 21-902(a) is the more serious charge: you were under the influence of alcohol, or your BAC was 0.08 or more per se. It carries up to 1 year in jail and 12 points. DWI under section 21-902(b) is the lesser charge for a smaller degree of alcohol impairment, carrying up to 2 months and 8 points.
Yes. Section 21-902(a)(1)(i) makes it an offense to drive under the influence of alcohol with no BAC reading required. The State proves it through the officer’s observations, your driving, the field sobriety tests, and the video. Refusing the breath test removes one piece of evidence, not the charge.
No. Cts. and Jud. Proc. section 10-307 is a rule of evidence, not a charging rule. It tells the court what a reading may presume: 0.08 or more is per se DUI, and 0.07 up to 0.08 is prima facie evidence of DWI. The State can still charge DUI or DWI at any BAC, or with none at all.
Law Offices of David R. Waranch — 301-563-9575 · toll-free 1-877-566-2408. Hablamos Español.
Last updated: August 2026. Statutory references: Md. Code, Transp. § 21-902; Cts. & Jud. Proc. § 10-307; Transp. § 16-205.1; Transp. § 16-113; Crim. Proc. § 6-220. This page is general information about Maryland law, not legal advice, and reading it does not create an attorney-client relationship.