Oregon Revised Statutes Insurance § 742.536

(1) When an authorized motor vehicle liability insurer has furnished personal injury protection benefits, or an authorized health insurer has furnished benefits, for a person injured in a motor vehicle accident, if such injured person makes claim, or institutes legal action, for damages for such injuries against any person, such injured person shall give notice of such claim or legal action to the insurer by personal service or by registered or certified mail. Service of a copy of the summons and complaint or copy of other process served in connection with such a legal action shall be sufficient notice to the insurer, in which case a return showing service of such notice shall be filed with the clerk of the court but shall not be a part of the record except to give notice.

(2) The insurer may elect to seek reimbursement as provided in this section for benefits it has so furnished, out of any recovery under such claim or legal action, if the insurer has not been a party to an interinsurer reimbursement proceeding with respect to such benefits under ORS 742.534 and is entitled by the terms of its policy to the benefit of this section. The insurer shall give written notice of such election within 30 days from the receipt of notice or knowledge of such claim or legal action to the person making claim or instituting legal action and to the person against whom claim is made or legal action instituted, by personal service or by registered or certified mail. In the case of a legal action, a return showing service of such notice of election shall be filed with the clerk of the court but shall not be a part of the record except to give notice to the claimant and the defendant of the lien of the insurer.

(3) If the insurer so serves such written notice of election and, where applicable, such return is so filed:

(4) As used in this section, “makes claim” or “claim” refers to a written demand made and delivered for a specific amount of damages and which meets other requirements reasonably established by the director's rule.