Wash. Rev. Code § 48.18.452
A policy of life insurance may designate as beneficiary a trustee or trustees named or to be named by will, if the designation is made in accordance with the provisions of the policy and the requirements of the insurance company. Immediately after the proving of the will the proceeds of such insurance shall be paid to the trustee or trustees named therein to be held and disposed of under the terms of the will as they exist at the death of the testator, but if no qualified trustee makes claim to the proceeds from the insurance company within one year after the death of the insured, or if satisfactory evidence is furnished the insurance company within such one-year period showing that no trustee can qualify to receive the proceeds, payment shall be made by the insurance company to those thereafter entitled. The proceeds of the insurance as collected by the trustee or trustees shall not be subject to debts of the insured and inheritance tax to any greater extent than if such proceeds were payable to any other named beneficiary other than the estate of the insured. Enactment of this section shall not invalidate previous life insurance policy beneficiary designations naming trustees of trusts established by will.
RCW 48.18.452