Oregon Revised Statutes Domestic Relations § 109.100

(1) Any minor child or the administrator may, in accordance with ORCP 27 A, apply to the circuit court in the county in which the child resides, or in which the natural or adoptive father or mother of the child may be found, for an order upon the child's father or mother, or both, to provide for the child's support. The child or the administrator may apply for the order by filing in the county a petition setting forth the facts and circumstances relied upon for the order. If satisfied that a just cause exists, the court shall direct that the father or mother appear at a time set by the court to show cause why an order of support should not be entered in the matter.

(2) The petitioner shall state in the petition, to the extent known:

(3) The petitioner shall include with the petition a certificate regarding any pending support proceeding and any existing support order. The petitioner shall use a certificate that is in a form established by court rule and include information required by court rule and subsection (2) of this section.

(4) The judgment of a court under subsection (1) of this section is final as to any installment or payment of money that has accrued up to the time either party makes a motion to set aside, alter or modify the judgment, and the court may not set aside, alter or modify the judgment, or any portion thereof, that provides for any payment of money that has accrued prior to the filing of the motion.

(5) The provisions of ORS 108.120 apply to proceedings under subsection (1) of this section.

(6) In any proceeding under this section, both the child's physical and legal custodians are parties to the action.