Declares that inpatient treatment may not exceed one hundred twenty days in RCW 13.40.165.

Provides that when an adjudicated offender is ordered to be confined pursuant to a disposition or modification order, the court may grant credit for time served or to be served in a voluntary substance abuse or mental health inpatient treatment facility, even though such facility is not a "detention facility" as defined by RCW 13.40.020.