This bill amends RCW 46.61.502, 46.61.504, and 46.61.5055 (and related cross-references) to change how driving or being in actual physical control while under the influence is defined, proved, and punished. It establishes per se concentration thresholds measured within two hours after driving or control: alcohol at 0.08 or higher (breath or blood) and THC at 5.00 nanograms per milliliter of whole blood (blood test). It permits an evidentiary affirmative defense that the defendant consumed alcohol or cannabis after driving or control but before testing if the prosecution is given notice before omnibus or pretrial hearing. Analyses taken more than two hours after driving may be admitted as evidence for concentration and impairment if they show any amount above 0.00. The bill generally keeps the offenses classified as gross misdemeanors but lowers the number of prior offenses needed for felony elevation from three to two within specified timeframes. The bill modifies penalties and sentencing procedures. It sets detailed mandatory minimum jail terms, fines, and monitoring alternatives for offenders with no prior offenses, one prior within seven years, and two priors within seven years, with different ranges depending on measured alcohol concentration (less than 0.15 versus at least 0.15) or test refusal. Sentencing alternatives include electronic home monitoring (EHM) and 24/7 sobriety program monitoring with specified minimum durations; courts may order ignition interlock devices on all motor vehicles operated by a convicted person and may require alcohol detection monitoring while on EHM. Costs for EHM and alcohol monitoring devices are generally borne by the offender and set by the county or municipality. The bill requires written findings when mandatory minimums are suspended or converted and authorizes expanded substance use disorder assessment and treatment where appropriate. The measure adds enhanced penalties tied to having a passenger under age 16, including additional consecutive jail time, higher fines per passenger, and extended ignition interlock periods. It prescribes license suspension, revocation, and probation conditions tied to concentration, refusal, and prior offenses, including day-for-day credit rules for prior suspensions and a 30-day confinement penalty for violations of mandatory probation conditions. The act defines what counts as a "prior offense" (including listed Washington statutes, certain out-of-state equivalents, deferred prosecutions, and deferred sentences) and defines the "within seven years" and "within 15 years" timing by reference to arrest dates. The act takes effect January 1, 2026. Some statutory text and subsections are truncated or missing from the extracted material (for example portions of RCW 46.61.5055 and several subsection continuations and the identity of a referenced “department”), so full details and placement of every provision in the updated statutes cannot be confirmed from these facts alone.

If enacted, the bill makes it easier for prosecutors to pursue per se DUI cases by tying alcohol to a 0.08 threshold and THC to a 5.00 ng/mL threshold measured within two hours of driving, while also allowing a narrow post-driving consumption defense if the defense gives notice. It lowers the number of prior offenses that can trigger felony treatment from three to two, raises mandatory minimum jail time and monitoring for repeat offenders, adds specified extra jail time, fines, and extended ignition-interlock requirements when a passenger under 16 is present, and creates strict probation rules (including 30 days in jail for each probation violation). Many cases will also require ignition interlock, electronic home monitoring, or 24/7 sobriety monitoring, and courts must order expanded substance use assessments and state written reasons when they deviate from mandatory minimums. The most affected parties are people charged with DUI (who will face higher and more structured penalties, longer monitoring, and direct costs for monitoring devices), courts and prosecutors (who must handle new notice rules, written findings, and order/oversee monitoring and treatment), counties and cities (which set electronic monitoring fees and must coordinate availability of 24/7 programs), and alcohol-monitoring and ignition-interlock providers. Offenders will likely pay more out of pocket for monitoring and longer license suspensions; local governments and courts may face increased administrative and program-management burdens. Some implementation details are unclear from the provided text—for example which state department sets interlock rules in the bill text and how availability of verified 24/7 programs will affect sentencing in all counties.