Wash. Rev. Code § 48.20.385
An insurer may not deny coverage for the treatment of an injury solely because the injury was sustained as a consequence of the insured's being intoxicated or under the influence of a narcotic.
RCW 48.20.385
Finding-2004 c 112: "The legislature finds that an alcohol or drug-related injury that requires treatment in an emergency department can be a critical moment in the life of a person with a substance abuse problem. Studies have demonstrated that appropriate interventions by hospital staff at these times can reduce substance abuse and lower future health care costs. The perception among health care providers that they may be penalized by insurers for conducting these interventions prevents many of them from performing interventions which can make all the difference to a person at the crossroads of a substance abuse problem." [ 2004 c 112 s 1.]
Application-2004 c 112: "This act applies to all contracts issued or renewed on or after June 10, 2004." [ 2004 c 112 s 7.]