Revised Code of Washington section 7.70.100 explains the procedures for medical malpractice mediation. "All causes of action, whether based in tort, contract, or otherwise, for damages arising from injury occurring as a result of health care provided after July 1, 1993, shall be subject to mandatory mediation prior to trial." The rule further provides that the Washington Supreme Court shall develop procedures to implement the mandate according to specifications indicated by the statute.
Washington Revised Code 7.70.100: Mandatory Mediation of Health Care Claims
Washington General Assembly. Revised Code of Washington, Jan. 1, 2013https://app.leg.wa.gov/rcw/default.aspx?cite=7.70.100