Washington State DUI Laws: Penalties for a First Offense

A driving under the influence (DUI) charge in Washington is a criminal matter, not a traffic infraction like the tickets handled through Washington’s traffic ticket and hearing process. The offense, the penalty schedule, and the license consequences are set by the Revised Code of Washington, and they climb with a driver’s alcohol concentration and with any prior offenses within seven years.

What counts as a DUI in Washington

Washington treats driving under the influence as a crime, not an infraction. Under RCW 46.61.502, a person commits DUI by driving with, within two hours of driving, a breath or blood alcohol concentration of 0.08 or higher, or a THC (active marijuana) concentration of 5.00 or higher. A driver can also be convicted for being under the influence of or affected by alcohol, cannabis, or any drug, even without a test result at those levels. A first-offense DUI is a gross misdemeanor, which carries a maximum of 364 days in jail and a $5,000 fine.

The alcohol reading matters for more than proving the charge. A concentration of 0.15 or higher, or a refusal to take the breath test, raises the mandatory minimum penalties at sentencing. Holding a lawful prescription or a medical marijuana authorization is not a defense to driving while affected by the drug.

Penalties for a first-offense DUI

Penalties escalate with the alcohol reading and with prior offenses. The mandatory minimums for a first offense, meaning no prior offense within seven years, are set by RCW 46.61.5055 and, as of 2026, fall into two tiers.

For a first offense with a BAC below 0.15, the court must impose at least 24 consecutive hours in jail and a fine of at least $350, up to the $5,000 maximum. In place of the 24-hour jail term, a judge may order at least 15 days of electronic home monitoring or a 90-day period of 24/7 sobriety program monitoring.

For a first offense with a BAC of 0.15 or higher, or where the driver refused the breath test, the mandatory minimum rises to 48 consecutive hours in jail and a fine of at least $500. The judge may substitute at least 30 days of electronic home monitoring or a 120-day period of sobriety monitoring.

On top of the fine, RCW 46.61.5054 adds a mandatory $250 fee for anyone convicted of, sentenced to a lesser charge for, or granted deferred prosecution after a DUI arrest. Courts impose other assessments as well, and a convicted driver pays the cost of any electronic home monitoring.

Losing your license: two separate actions

A Washington DUI can suspend a driver’s license in two separate ways, and they run on different tracks.

The first is an administrative action by the Department of Licensing based on the arrest itself, under the implied consent law in RCW 46.20.3101. A driver who takes the test and registers 0.08 or higher, or THC 5.00 or higher, faces a 90-day suspension for a first incident within seven years. A driver who refuses the test faces a one-year revocation for a first refusal. This action can proceed even if the criminal case is later dismissed, unless the driver requests a hearing and prevails.

The second is the court’s action on conviction, under RCW 46.61.5055. For a first offense below 0.15, the license is suspended 90 days; at 0.15 or higher, it is revoked for one year. Because the two actions are separate, one arrest can produce both the administrative penalty and the conviction penalty.

The ignition interlock requirement

Washington requires an ignition interlock device, a breath-testing unit wired to the ignition, for most people convicted of DUI. Under RCW 46.20.720, the Department of Licensing requires the device before a driver’s license is reinstated and as a condition of an ignition interlock driver’s license.

A driver who needs to drive during a suspension usually applies for an ignition interlock driver’s license, which allows driving only in a vehicle equipped with a functioning device. The driver pays for installation, monthly monitoring, and removal.

How penalties increase beyond a first offense

Washington counts prior offenses within a seven-year window, and each prior sharply raises the mandatory minimums in RCW 46.61.5055. A second offense within seven years carries a mandatory minimum measured in days of jail rather than hours, plus a two-year license revocation; a third or subsequent offense brings a longer jail term and a three-year revocation.

A DUI becomes a felony under RCW 46.61.502 when the driver has four or more prior offenses within ten years, or a prior conviction for felony DUI, vehicular homicide, or vehicular assault involving impaired driving. A felony DUI is prosecuted in superior court and carries prison exposure rather than jail.

How a Washington DUI case moves through court

A first-offense DUI is a gross misdemeanor, so the case is filed in a court of limited jurisdiction, a district court or a city municipal court, and follows the Criminal Rules for Courts of Limited Jurisdiction (CrRLJ). The case begins with an arraignment, where the defendant enters a plea, and can resolve through a negotiated plea, a dismissal, or a bench or jury trial followed by sentencing on conviction.

Washington also offers deferred prosecution as an alternative for defendants whose driving stemmed from alcoholism, drug addiction, or a mental health condition. Under chapter 10.05 RCW, a defendant who petitions for deferred prosecution agrees to a multi-year treatment program, and completing it can lead to dismissal, but a person may use deferred prosecution only once in a lifetime. A defendant convicted in a court of limited jurisdiction may appeal for a new trial in superior court.