Wash. Rev. Code § 43.101.125
A peace officer's certification lapses automatically when there is a break of more than twenty-four consecutive months in the officer's service as a full-time law enforcement officer. A break in full-time law enforcement service which is due solely to the pendency of direct review or appeal from a disciplinary discharge, or to the pendency of a work-related injury, does not cause a lapse in certification. The officer may petition the commission for reinstatement of certification. Upon receipt of a petition for reinstatement of a lapsed certificate, the commission shall determine under this chapter and any applicable rules of the commission if the peace officer's certification status is to be reinstated, and the commission shall also determine any requirements which the officer must meet for reinstatement. The commission may adopt rules establishing requirements for reinstatement.
RCW 43.101.125