Washington Revised Code Title 74. Public Assistance § 74.20A.290. Applicant for adjudicative proceeding must advise department of current address

Whenever any person files an application for an adjudicative proceeding under RCW 74.20A.055 or 74.20A.270, after the department has notified the person of the requirements of this section, it shall be the responsibility of the person to notify the department of the person's mailing address at the time the application for an adjudicative proceeding is made and also to notify the department of any subsequent change of mailing address during the pendency of the administrative proceeding and any judicial review. Whenever the person has a duty under this section to advise the department of the person's mailing address, mailing by the department by certified mail to the person's last known address constitutes service as required by chapters 74.20A and 34.05 RCW.