Maryland DUI & DWI Laws Explained

By Javier Marín, Editor·Last reviewed September 2026·How we check this

Maryland is the only U.S. state that splits ordinary impaired driving into two separate offenses: DUI (Driving Under the Influence) under Transportation Article §21-902(a), and a less severe DWI (Driving While Impaired) under §21-902(b). Both can stem from the same traffic stop, and prosecutors often charge them in the alternative — meaning a defendant could be convicted of one but not the other.

The two-tier threshold

Maryland's per-se thresholds:

DUI under §21-902(a): 0.08% BAC or higher — the standard impaired-driving offense recognized in every state.
DWI under §21-902(b): 0.07-0.079% BAC, OR observed impairment from alcohol/drugs without reaching the 0.08% threshold.
Drivers under 21: 0.02% BAC under Maryland's zero-tolerance rule.
Commercial drivers (CDL): 0.04% BAC.

Maryland is unusual in punishing the 0.07-0.079% range as a standalone, lesser offense. Most other states either do not charge below 0.08% at all or fold it into a "lesser-included offense" that's subject to the prosecutor's discretion.

The MVA hearing window

After a DUI or DWI arrest with a chemical-test failure or refusal, the officer typically takes the driver's license on the spot and issues a 45-day temporary paper license. Maryland gives the driver 10 days to request an MVA hearing in writing — same paper notice from the arrest. The MVA hearing addresses three narrow questions: did the officer have lawful cause for the stop and arrest, was the BAC at or above the relevant threshold, and did the driver lawfully take or lawfully refuse the chemical test.

Winning the MVA hearing prevents the administrative suspension from going forward. Losing it converts the temporary license to a full suspension on day 46. The MVA hearing is separate from the criminal court case — a driver can win one and lose the other.

First-offense DUI penalties (criminal)

A first-offense DUI under §21-902(a) typically produces:

Up to 1 year in jail (often suspended on first offenses without aggravators).
Fine up to $1,000, plus court costs.
6-month MVA license suspension (concurrent with the administrative suspension).
Mandatory completion of a state-licensed Alcohol Education and Treatment Program (12-26 weeks depending on screening).
Mandatory ignition interlock device (IID) on the offender's primary vehicle for the restricted-license period (typically 180 days for first offense; longer for higher BAC).
SR-22 financial responsibility filing for 3 years — see Maryland insurance.
12 points on the Maryland record — automatic revocation; reinstatement only after suspension period and program completion. See Maryland point system.
3 years of supervised probation in most cases.

First-offense DWI penalties (criminal)

A DWI under §21-902(b) is the lower-tier offense — but still a misdemeanor:

Up to 2 months in jail (rarely imposed on first offense).
Fine up to $500, plus court costs.
60-day MVA license suspension (or restricted license with IID).
Mandatory Alcohol Education and Treatment Program (typically the shorter 12-week version).
SR-22 financial responsibility filing for 3 years.
8 points on the Maryland record.

Aggravating factors

Penalties escalate quickly for either offense when:

BAC at or above 0.15% (extended IID and suspension).
An accident with injury or property damage (separate charges may apply).
A child under 16 in the vehicle (mandatory minimum jail time, separate child-endangerment exposure).
Refusal of chemical test (270-day suspension first time; 2-year second time).
Excessive speed at the time of arrest.
A prior DUI or DWI within the lookback period (Maryland uses a 5-year lookback for sentence enhancements).

Ignition interlock devices

Maryland requires an IID on every vehicle the offender owns or operates as a condition of the restricted license after a DUI conviction (and many DWI convictions, particularly with BAC at or above 0.08%). The device costs about $70-$120/month plus a $100-$150 install fee. The IID provider downloads data monthly to the MVA; failed tests can extend the IID period or trigger a re-suspension. Maryland's IID program covers nearly 30,000 active devices statewide.

Repeat offenses

A second DUI within 5 years brings mandatory minimum jail time (5 days minimum), 1-year license suspension, and a 1-year IID requirement. A third DUI within 5 years is a felony in Maryland under specific circumstances (e.g., causing serious injury). Maryland uses a 5-year lookback for sentence enhancement on repeat DUI/DWI offenses, with a separate lifetime lookback for certain habitual-offender designations.

For the points associated with each conviction, see Maryland point system. For reinstatement, see Maryland suspended license.