RCW 48.10.260: Action against subscriber requires judgment against insurer.

(1) No action shall lie against any subscriber upon any obligation claimed against the insurer until a final judgment has been obtained against the insurer and remains unsatisfied for thirty days.

(2) Any such judgment shall be binding upon each subscriber only in such proportion as his or her interests may appear and in an amount not exceeding his or her contingent liability, if any.