Oregon Revised Statutes Occupations and Professions § 701.420

(1) Partial payment is allowed and may be made on contracts for construction and home improvement. An owner, contractor or subcontractor may withhold as retainage an amount equal to not more than five percent of the contract price of the work completed. Partial payment allowed under this subsection is not acceptance or approval of some of the work or a waiver of defects in the work.

(2) The owner, contractor or subcontractor shall pay interest at the rate of one percent per month on the final payment due the contractor or subcontractor. The interest shall commence 30 days after the contractor or subcontractor has completed and the owner has accepted the work under the contract for construction for which the final payment is due. The interest shall run until the date when final payment is tendered to the contractor or subcontractor. When the contractor or subcontractor considers the work that the contractor or subcontractor is contracted to perform to be complete, the contractor or subcontractor shall notify the party to whom the contractor or subcontractor is responsible for performing the construction work under the contract. The party shall, within 15 days after receiving the notice, either accept the work or notify the contractor or subcontractor of work yet to be performed under the contract. If the party does not accept the work or does not notify the contractor or subcontractor of work yet to be performed within the time allowed, the interest required under this subsection shall commence 30 days after the end of the 15-day period.

(3) When a contractor pays a subcontractor in full, including the amount the contractor withheld as retainage, the owner with whom the contractor has the contract shall pay the contractor, out of the amount that the owner withheld from the contractor as retainage, a sum equal to the amount of retainage that the contractor paid the subcontractor. The contractor shall notify the owner when the contractor pays a subcontractor in full under this section and the owner shall, within 15 days after receiving the notice, pay the contractor the amount due the contractor under this subsection. Interest on the amount due the contractor at the rate of one percent per month shall commence 30 days after the owner receives notice of full payment to the subcontractor.