Wash. Rev. Code § 26.26A.750
(1) Except as otherwise provided in RCW 26.26A.740(3) or 26.26A.755, before, on, or after the birth of a child conceived by assisted reproduction under a gestational surrogacy agreement, a party to the agreement may commence a proceeding in the superior court for an order or judgment:
[ 2018 c 6 s 711.]