Wash. Rev. Code § 48.18.375
A person whose life is insured under a group insurance policy may, subject and pursuant to the terms of the policy, or pursuant to an arrangement between the insured, the group policyholder and the insurer, assign to any or all his or her spouse, children, parents, or a trust for the benefit of any or all of them, all or any part of his or her incidents of ownership, rights, title, and interests, both present and future, under such policy including specifically, but not by way of limitation, the right to designate a beneficiary or beneficiaries thereunder and the right to have an individual policy issued to him in case of termination of employment or of said group insurance policy. Such an assignment by the insured, made either before or after July 16, 1973, is valid for the purpose of vesting in the assignee, in accordance with any provisions included therein as to the time at which it is to be effective, all of such incidents of ownership, rights, title, and interests so assigned, but without prejudice to the insurer on account of any payment it may make or individual policy it may issue prior to receipt of notice of the assignment. This section acknowledges, declares, and codifies the existing right of assignment of interests under group insurance policies.
RCW 48.18.375