Washington Revised Code Title 43. State Government--Executive § 43.43.138. Establishing, restoring service credit

(1) Establish allowable membership service not previously credited;

(2) Restore all or a part of that previously credited membership service represented by withdrawn contributions; or

(3) Restore service credit represented by a lump sum payment in lieu of benefits, before the deadline established by statute, may do so under the conditions set forth in RCW 41.50.165.