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Jefferson County,
Est. 1818
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Real Estate Information


Real Estate Information


How is my real estate value determined?


Jefferson County, as with most counties in Missouri, primarily values real estate for tax purposes using mass appraisal methodology. This method first determines the current replacement cost of all improvements, less any depreciation of those improvements. The depreciated value of these improvements is added to the value of the land to determine the fair market value of the property. The mass appraisal method is recognized as being one of the most efficient and fair methods of valuing many properties over a wide area.



When is my property reassessed?

State law requires all real property to be reassessed each odd numbered year. Reassessment does not necessarily mean the value of property will increase or decrease. Information and data pertaining to real estate values and costs are collected by the Assessor’s Office. Analysis and studies are performed to determine how the real estate market has changed and how it has affected assessed values. The conclusions determined from the data collected are used to determine if any changes are made to real estate values of the current reassessment year.  


What is market value and assessed value?

 A simple definition of market value is the price the property would bring when offered for sale by a person who is willing but not obligated to sell it, and is bought by a person who is willing to purchase it but who is not forced to do so. Assessed value is a percentage of the market value based upon the classification, which is determined by the type of property or how it is used. By state statute the Missouri Legislature has set three classifications of real property and the assessment level for each. The classifications and assessment levels for each are: Commercial real property at 32%, Residential real property at 19% and Agricultural real property at 12%. 



For example:

$100,000 market value X 19% residential assessment level = $ 19,000 assessed value



Why would my assessment or taxes increase?

There are several factors that can affect the assessed value or taxes other than reassessment. Some of the things that could affect the assessed value are: physical changes to the property such as an addition or other new construction, the previous value may have been a prorated value based upon the date of occupancy and the new value reflects the full year value or additional acreage may have been added to the real estate parcel.



The actual tax amount may also change from year to year without any change to your assessed value. The tax rate applicable to your property may change, thus resulting in a change to your tax amount. Your tax rate is determined by a combination of levies for the school, fire, ambulance and other taxing entities that apply to your property. These levies can be changed by either the entities or by voter approval. If the tax rate increases then your taxes may increase with no change to your assessed value.


Is there an appeal process?  If you feel the Assessor’s value does not reflect the fair market value of your property first call the Assessor’s Office. They will review the information in your file with you and examine any information pertaining to the value you wish to present. After discussing the value of your property with the Assessor’s Office and you are not satisfied, you can file an appeal before the Board of Equalization (BOE). The appeal must be filed before the second Monday in July of each year. To file an appeal you must contact the County Clerk’s Office at (636) 797-5478.


If you are not satisfied with the Board of Equalization decision you may further appeal to the Missouri State Tax Commission. Information will be provided to you by the County Clerk’s Office.


Destroyed Residential Property

Section 137.082, RSMo allows the assessor to remove the value of residential property, on a pro rata basis, which was destroyed by a natural disaster such as a tornado, flood, fire, or earthquake.  The following claim form must be completed in order to received such a reduction in value.


Please review instructions on the form, fill out and mail, fax, or bring in to the Jefferson County Assessor's Office.


Claim Form For Destroyed Residential Property


Change Mailing Address on Real Estate Parcel

If you need to change the mailing address on your real estate parcel please email Real Estate Address Change to

How can I contact your office?

Give us a call at (636) 797-5466 or 1-800-748-3456. Our fax number is (636) 797-5470. Our email address is We are open Monday through Friday 8:00am to 5:00pm.