NEW UPDATES!
OARs governing county retention were updated November 2025. Your Multnomah County Retention Series has been updated accordingly. Please make sure to double check - some series may have new retention periods.
Series Title (Agency Series #)
Description. (Legal Citations)
Retention
Ratio Report (DART12-002)
Used to report appraisal values between reappraisals of property to the Department of Revenue and to maintain a historical record of this analysis. Information on the report may include property sales by neighborhood or reappraisal areas, ratio of sales to property values, previous study statistics, and individual sales listings. (OAR 166-150-0015(18))
Retention:
Retain permanently.
Ratio Study Working Files (DART12-001)
Used to update appraisal values in the TSG system between reappraisals of property. It is also used to prepare the annual Ratio Report. May include sales data cards, sales verifications, spreadsheets, and supporting documents. (OAR 166-150-0015(18)) (OAR 166-017-0045(2,4)) (MCC § 8.500)
Retention:
Retain permanently - transfer to Archives upon becoming inactive or after 10 years, whichever comes first.