Wash. Rev. Code § 43.334.080
In furtherance of the policy of the state to cooperate with the federal government in all of the programs under the jurisdiction of the department, rules as may become necessary to entitle the state to participate in federal funds may be adopted, unless expressly prohibited by law. Any internal reorganization carried out under the terms of this chapter shall meet federal requirements that are a necessary condition to state receipt of federal funds. Any section or provision of law dealing with the department that may be susceptible to more than one construction shall be interpreted in favor of the construction most likely to comply with federal laws entitling this state to receive federal funds for the various programs of the department. If any law dealing with the department is ruled to be in conflict with federal requirements that are a prescribed condition of the allocation of federal funds to the state, or to any departments or agencies thereof, the conflicting part is declared to be inoperative solely to the extent of the conflict.
RCW 43.334.080