Washington DUI Laws

The per-se alcohol limit is 0.08 within two hours after driving. Washington also has a codified cannabis limit: 5.00 nanograms of THC per milliliter of whole blood. You can also be convicted on an impairment theory with no specific number if alcohol, cannabis, or any drug affects your driving. The commercial limit is 0.04, and drivers under 21 face a 0.02 alcohol limit (or any measurable THC).

Washington’s penalty schedule has only two bands within each tier: under 0.15, and 0.15-or-higher (a refusal is penalized in this same higher band). Landing in the higher band raises the mandatory jail floor, the non-suspendable fine floor, and the length of the license loss. There is no additional super-band above 0.15. A refusal is not a separate crime, but it can be used against you in the criminal trial and triggers a separate administrative license revocation.

For a first offense with no prior in 7 years and a result under 0.15: 24 consecutive hours to 364 days in jail (electronic home monitoring or a 24/7 sobriety program can substitute for mandatory jail), a $350 non-suspendable fine up to $5,000, and a 90-day license suspension. At 0.15 or higher or on a refusal: a 48-hour jail floor, a $500 fine floor, and a 1-year (0.15+) or 2-year (refusal) revocation. An ignition interlock device is mandatory for at least one year.

For a second offense within 7 years and a result under 0.15: 30 days in jail plus 60 days of electronic home monitoring, a $500 fine floor up to $5,000, and a 2-year revocation. At 0.15 or higher or on a refusal: 45 days plus 90 days of monitoring, a $750 fine floor, and a 900-day (0.15+) or 3-year (refusal) revocation. An ignition interlock device is mandatory, with a five-year restriction minimum.

A third DUI (two priors in 7 years) is still a gross misdemeanor capped at 364 days — so the felony generally begins at the fourth offense. A DUI is a class B felony only when the driver has 3 or more prior offenses within 15 years, or has ever been convicted of a felony DUI/physical control, vehicular homicide, or vehicular assault committed while under the influence. The class B felony maximum is 10 years and $20,000, though the actual sentence is set by the Sentencing Reform Act standard range.

Two separate tracks apply. The Department of Licensing imposes an administrative action (90 days for a first test failure, 1–2 years for a refusal or repeats) under RCW 46.20.3101, and the court imposes a conviction-based action (a 90-day suspension up to multi-year revocations) under RCW 46.61.5055(9). The two overlap with day-for-day credit. Higher tiers are revocations, which do not auto-return at the end of the period. You can apply immediately for an ignition interlock driver’s license (RCW 46.20.385) to keep driving throughout.

Yes. The court must require an ignition interlock device on every vehicle you operate for any DUI or physical-control conviction (RCW 46.61.5055(5)(a)). The post-reinstatement restriction runs at least 1 year for a first restriction, 5 years for a second, and 10 years for a third (RCW 46.20.720(3)(c)), with a 0.020 alcohol set point. Each passenger under 16 adds a 12- or 18-month extension. An ignition interlock driver’s license lets you keep driving during the license loss.

Implied consent covers the breath test; a blood test generally needs a warrant. Refusing is not a separate crime, but it has three consequences: the Department of Licensing revokes your license for at least 1 year (2 years for a repeat) under RCW 46.20.3101, the refusal can be used against you at the criminal trial (RCW 46.20.308(2)(b)), and in the penalty schedule a refusal is treated like a 0.15-or-higher result.

A driver under 21 with an alcohol concentration of at least 0.02 but below the adult 0.08 limit, or any measurable THC above 0.00, commits a standalone misdemeanor under RCW 46.61.503 (up to 90 days in jail and a $1,000 fine), separate from the adult penalty grid. The Department of Licensing also imposes a 90-day administrative suspension for a first incident, or 1 year for a repeat. A driver under 21 who tests at or above the adult limits is charged as an adult instead.

Yes. Washington sets a per-se cannabis limit of 5.00 nanograms of THC per milliliter of whole blood, and you can also be convicted for being under the influence of or affected by any drug, or a combination of alcohol and drugs. Having a valid prescription or legally using cannabis is not a defense (RCW 46.61.502(2)). Combined alcohol-and-drug impairment also counts.

Negligent driving in the first degree (RCW 46.61.5249) is a misdemeanor often used as a reduced charge from DUI. Deferred prosecution (chapter 10.05 RCW) is a treatment-based alternative. Both can keep a DUI conviction off your record, but both count as "prior offenses" if you are arrested for DUI again, and an ignition interlock may still be required. Treat them as off-ramps with lasting consequences, not clean escapes.

Causing substantial bodily harm while under the influence is vehicular assault, a class B felony (up to 10 years). Causing a death within three years is vehicular homicide, a class A felony (up to life), with two years added per prior offense on the under-the-influence prong. A passenger under 16 adds mandatory jail (24 hours / 5 days / 10 days by offense count), an added fine, and a 12- or 18-month ignition-interlock extension per child.