Property Assessment FAQs

The information on this page will help you understand how the assessor determines the Real Market Value and Assessed Value for each property in Multnomah County.

The amount of taxes you owe is based on these values. How your tax bill is calculated.

Review the following information for answers to many frequently asked questions.

Look up your property value

View your tax statement, check your property value, taxes due, property description, and much more at www.MultCoPropTax.com

• Use the “Guest Login” button to search by Property Account Number (e.g. R176816) or street address. You do not need a password to log on as a guest.
• Expand your search capabilities with subscription access.

History of property values and taxes

See a graph of the last five years of your property value and taxes.

Property Tax Basics Video

Learn more with this Property Tax Basics Video.

How is my Assessed Value (AV) determined?

Assessed Value (AV) is the lower of last year’s Maximum Assessed Value (MAV) plus 3%, or the current Real Market Value (RMV). This value provides the baseline for your tax bill calculation.

How is my Real Market Value (RMV) determined?

Per Oregon Revised Statute (ORS) 308.205(1): Real market value of all property, real and personal, means the amount in cash that could reasonably be expected to be paid by an informed buyer to an informed seller, each acting without compulsion in an arm’s-length transaction occurring as of the assessment date for the tax year.

The above is part of the definition, the remainder is under ORS 308.205 (2)(a)(b)(c) and (d). Please reference the link above for the complete definition of Real Market Value (RMV).

To estimate the RMV of your property, the Assessor’s office appraises your property using a variety of data collection and other methods including:

• Physical Inspection
• Statistical Analysis of Market Trends
• Comparison of sale prices and characteristics of similar properties
• Analysis of building plans and other public records

How is my Maximum Assessed Value (MAV) determined?

Maximum Assessed Value (MAV) was established by Ballot Measure 50 for the 1997-98 tax year. 

Assuming no changes are made to the property, MAV is calculated as the greater of 103% of the prior year's assessed value (AV), or 100 percent of the prior year's MAV.

MAV’s for properties that existed prior to 1995 were set based on the 1995-1996 Real Market Value (RMV) less 10%. MAVs for “new” properties (constructed or created after 1995) are set by multiplying the property's Real Market Value (RMV) as of the assessment date of January 1st following the year of construction or creation by the Changed Property Ratio (CPR) for that year.

MAV is the only component of your property taxes where a 3% increase limit applies. However, your MAV can increase above 3 percent of the prior year's assessed value if certain changes, known as exceptions, are made to your property.

For more information about Maximum Assessed Value, please refer to the Oregon Department of Revenue’s Maximum Assessed Value manual.

Why did my Assessed Value increase so much?

Your Assessed Value (AV) can increase for two reasons:

1. An Exception Event (see below)

2. If your previous year’s Real Market Value was lower than your Maximum Assessed Value and now your Real Market Value is more than your Maximum Assessed value, you may see a jump in your Assessed Value, depending on how low your RMV was in previous years.

See a graph of the last five years of your property value and taxes.

For information regarding the Assessed Value for a specific property, please contact our customer service department by phone (503) 988-2225 or by email at propertytax@multco.us. Have your account number or property ID available.

What is an Exception event?

Ballot Measure 50 limits MAV increases to 3% per year except under certain circumstances including, but not limited to:

• New Construction/Additions valued at more than $18,200 in one year or $45,000 over 5 years
• Remodeling, renovation or rehabilitation valued at more than $18,200 in one year or $45,000 over 5 years
• Partitioning or subdivision
• Rezoning (where the property is used consistently with the new zoning)
• Discovery of omitted Property
• Disqualification from exemption or special assessment

In these cases, the Assessor appraises the property to determine how much Real Market Value was added by the change(s) to the property."

Please refer to ORS 308.149 and OAR 150-308-0160 for more information

What is ongoing maintenance?

General Ongoing Maintenance and Repair refers to maintenance and repair items completed over a period of years as-needed, and, with multifamily properties, scheduled to take place. This is in contrast to rehabilitation and/or renovation where many components of the property are replaced within a short period of time for a residential property, and/or a short time period involving many units for income properties.
Please refer to OAR 150-308-0130 for more information.

I recently bought my house and have not done any work to it. Why was Exception value added?

Property values and taxes on real property are tied to the property, not the owner. The previous owner may have done work to the property that was discovered at the time of sale.

What property does Multnomah County assess?

• Real Property - Residential, commercial, multifamily and industrial land and buildings.
• Business Personal Property - Includes furniture, fixtures, and equipment used in a business.
• Floating Property - Houseboats, boathouses, moorages and slips.
• Manufactured Structures

Why do I receive multiple tax bills?

Why do I receive multiple tax bills when I only have one property? Interested in consolidating your property?

Find your Account Number/Property ID

Your account number is the same as your property ID. It is listed at the top and the bottom of your tax statement.

Top of your tax bill:

Bottom of your tax bill: