Wash. Rev. Code § 41.50.630
In a hearing to quash, modify, or terminate the mandatory benefits assignment order, the court may grant relief only upon a showing that the mandatory benefits assignment order causes extreme hardship or substantial injustice. Satisfaction by the obligor of all past due payments subsequent to the issuance of the mandatory benefits assignment order is not grounds to quash, modify, or terminate the mandatory benefits assignment order. If a mandatory benefits assignment order has been in operation for twelve consecutive months and the obligor's spousal maintenance is current, the court may terminate the order upon motion of the obligor unless the obligee can show good cause as to why the mandatory benefits assignment order should remain in effect.
RCW 41.50.630
Severability-1991 c 365: See note following RCW 41.50.500.