Sunny · 84°

Assessment information for Boone County Property Owners

posted on 4/7/23

Boone County Home Owners,

You’ve recently received your 2023 assessment notice and are shocked.  Truth be told, I’m shocked!!  I’ve worked in an assessor office for 35 years and have never seen changes, like these, in assessed valuations for residential property.  Please remember that increased assessments do not equate to a similar percent of increase in property tax.  Assessments have increased significantly across the entire state of Iowa for 2023 and there is a built-in mechanism to suppress large increases in assessments from affecting taxable valuation, the rollback.  The rollback/assessment limitation is expected to decline dramatically to absorb the large increase in assessed valuation.  The current rollback is 54.65% and is estimated to reduce to 46.25% as the new assessments are added to the current base

So, will your property taxes change by the same percentage your assessment changed? The example, shown below, will give you an idea of how assessed values, rollbacks and levy rates are used to calculate property taxes.  In the first example, values went up while rollback and levy rates remained the same.  The following three examples show other scenarios.  The purpose of this illustration is to demonstrate that the percent of which your assessed value changes does not mean that your property taxes will change at the same percentage.  Remember, assessed values are the foundation from which property taxes are calculated.  Property tax laws, assessment limitations (rollbacks) and budgets by taxing bodies (including but not limited to: school, city, county, assessor, area school) that provide public services, determines the amount of property tax you pay.  Assessors do not raise revenues for taxing bodies, do not determine tax rates and do not calculate or collect property taxes.

Table Graphic

Therefore, it is unknown exactly how individual property taxes will be impacted with 2023 valuation changes at this time, since rollbacks for each class won’t be determined until fall of 2023 and budget levies will not be determined until early 2024 with tax statements being mailed in the fall of 2024.

Please know that our assessments would increase, no matter what.  The Iowa Department of Revenue (IDR) track normal arm’s length sales in each jurisdiction/county.  A Declaration of Value is provided with each sale and a corresponding sales ratio is calculated with each transaction, which is sent to the IDR.  When the median of all sales that transpired in the jurisdiction is 5% outside 100% of Market Value (95% - 105%) the IDR will equalize all assessments to 100%. 

“No matter what….” what would this mean in Boone County???  Say the assessor did nothing April 1st, and you didn’t receive an assessment roll.  The median sales ratio for residential sales (410) in Boone County in 2022 was 76.5.  This fall the Director of Revenue would order, via equalization, the Boone County Auditor to increase all assessed values of Residential property an increase not of 23.5%(23.5+76.5) but, (30.7%*76.5%) across the board, no matter the location, bringing assessments to 100%. 

Madrid, Boone, Ogden, stand-alone Rural Residential, Rural Subdivisions and small towns are all unique and have different market influences.   As the Boone County Assessor, it is my responsibility to place increases that match what is occurring in respective areas, not leaving revaluation to a blanket percentage.  The real estate market has changed in an unprecedented manner recently and your new assessment reflects these changes.  As required by law, the Assessor followed the direction of the market the past calendar year and will continue to do so, every odd year, as we work to maintain equitable assessments for all property owners in Boone County.


Please feel free to contact our office and request an appeal form or to discuss your assessment.  (515) 433-0508

Forms are also available at our website:


Paul Overton, Boone County Assessor

Did You Know

Sign up to receive notifications when board meetings and agendas are posted, job openings are announced, and more.

Customize Your Notifications

Mission Statement

The mission of Boone County is to be accountable to its citizens in providing innovative and high-quality government services in an economical, fair, professional, and courteous manner to enhance and protect the health, welfare, and safety of those who live and work in Boone County.