Oregon Revised Statutes Insurance § 734.430

(1) Published in such manner as shall be directed by the court; and

(2) Enclosed in a sealed envelope, addressed and mailed, postage prepaid, to each member or subscriber liable thereunder, at the last-known address of the member or subscriber as it appears on the records of the insurer, at least 20 days before the return day of the order to show cause specified in the assessment order.