Washington Revised Code Title 48. Insurance § 48.01.180. Adopted children--Insurance coverage

(1) A child of an insured, subscriber, or enrollee shall be considered a dependent child for insurance purposes under this title upon assumption by the insured, subscriber, or enrollee of a legal obligation for total or partial support of a child in anticipation of adoption of the child. Upon the termination of such legal obligations, the child shall not be considered a dependent child for insurance purposes.

(2) Every policy or contract providing coverage for health benefits to a resident of this state shall provide coverage for dependent children placed for adoption under the same terms and conditions as apply to the natural, dependent children of the insured, subscriber, or enrollee whether or not the adoption has become final.

(3) No policy or contract may restrict coverage of any dependent child adopted by, or placed for adoption with, an insured, subscriber, or enrollee solely on the basis of a preexisting condition of the child at the time that the child would otherwise become eligible for coverage under the plan if the adoption or placement for adoption occurs while the insured, subscriber, or enrollee is eligible for coverage under the plan.