DWI & DUI Laws
by State

National Overview

DWI & DUI Laws at a Glance

Impaired driving is illegal in every U.S. state, but the details differ significantly depending on where it happens. Even the name changes: DUI, DWI, OWI, OUI, and OVI are all state-specific terms for essentially the same offense, operating a vehicle while impaired above a legal threshold.

How BAC Testing and Implied Consent Work

BAC is measured through a breath, blood, or urine test under "implied consent" laws that exist in every state: driving on public roads counts as consent to testing when there's a lawful arrest for suspected impairment. Refusing the test triggers its own penalty, typically an automatic license suspension, independent of and in addition to any penalty from the underlying DWI charge.

Two Separate Tracks: Administrative and Criminal

Most states separate the administrative side (a motor vehicle agency suspension that can start almost immediately after arrest, sometimes before any conviction) from the criminal case working through court. These two tracks often run on different timelines, and resolving one doesn't automatically resolve the other.

What Varies by State

• First-offense license suspension length, commonly ranges from a few months to a year
• Ignition interlock device requirements, some states require one for every offender including first-time convictions; others only for repeat or high-BAC offenders
• Lookback period, how far back prior offenses count toward making a new charge a "repeat" offense, which affects penalty severity

Select your state below for the specific BAC limit, suspension period, and interlock requirement that applies where you are.

Common Questions

Frequently Asked Questions: DWI & DUI Laws

• What is the legal BAC limit for driving?
  0.08% is the standard threshold in nearly every U.S. state for drivers 21 and over. Every state sets a much lower zero-tolerance threshold (typically 0.02%-0.05%) for drivers under 21, and commercial drivers face a federal minimum standard of 0.04% regardless of state.
• What's the difference between DUI and DWI?
  In most cases, nothing legally significant. They're just different states' statutory names for the same underlying offense: operating a vehicle while impaired by alcohol or drugs above the legal threshold. Some states use different terms, and a few states use more than one term for different severity levels.
• What happens if I refuse a BAC test?
  Every state has an implied consent law: refusing a lawfully requested BAC test after a DWI arrest triggers its own penalty, typically an automatic license suspension, separate from and in addition to any penalty from the underlying charge itself.
• How long is a license suspended for a first offense?
  It varies by state, commonly ranging from a few months to about a year. Suspensions often run on two separate tracks, an administrative suspension that can start almost immediately after arrest, and any additional consequences tied to the criminal case.
• Is an ignition interlock device required after a DWI?
  It depends on the state. Some states require an interlock device for every offender, including first-time convictions; others only require it for repeat offenders or cases involving a high BAC. Check your state's specific page above for its current rule.