Hawaii Revised Statutes Division 2. Business § 431:10C-401

(a) A joint underwriting plan is established consisting of all insurers authorized to write and engage in writing motor vehicle insurance in this State, except those insurers writing motor vehicle insurance exclusively under section 431:10C-106.

(b) Each insurer shall be a member of the plan and shall maintain membership as a condition of its licensure to transact such insurance in this State.