Wash. Rev. Code § 25.15.436
(1) An organization other than a limited liability company may convert into a limited liability company, and a limited liability company may convert into an organization pursuant to this section and RCW 25.15.441 through 25.15.451 and a plan of conversion, if:
(2) A plan of conversion must be in a record and must include:
[ 2015 c 188 s 84.]