RCW 39.26.060: Cooperative purchasing.

(1) On behalf of the state, the department may participate in, sponsor, conduct, or administer a cooperative purchasing agreement for the procurement of any goods or services with one or more states, state agencies, local governments, local government agencies, federal agencies, or tribes located in the state, in accordance with an agreement entered into between the participants. The cooperative purchasing may include, but is not limited to, joint or multiparty contracts between the entities, and master contracts or convenience contracts that are made available to other public agencies.

(2) All cooperative purchasing conducted under this chapter must be through contracts awarded through a competitive solicitation process.