What Is an Assessor?

An assessor is a local government official who determines the value of a property for local real estate taxation purposes. The figures assessors derive are used to calculate future property taxes. The assessor estimates the value of real property within a city or town’s boundaries. This value is converted into an assessment, which is one component in the computation of real property tax bills.

Key Takeaways

  • An assessor is an expert who determines the appropriate valuation of an asset or property, often for purposes of taxation.
  • Assessors estimate taxable as well as fair market value based on several objective and subjective measures.
  • To become an assessor, you must be trained and certified. Certification requirements vary by state and municipality.

How Assessors Work

Assessors are government officials who maintain annual assessments at a uniform percentage of market value. An assessor signs an oath to this effect when certifying the tentative assessment roll. The assessment roll is a document containing each property assessment. Each year assessors are required to keep current the physical description, inventory, and value estimate of every parcel.

An assessment occurs when an asset's value must be determined for the purpose of taxation. Some assessments are made annually on certain types of property, such as homes, while others may be made only once. For example, homes are often valued every three or four years according to their physical condition and comparable values of surrounding residences.

Assessors are trained to determine the fair market value of property. Fair market value refers to the price that would be agreed upon between a willing and informed buyer and a willing and informed seller under usual and ordinary circumstances. It is the highest price a property would bring if it were for sale on the open market for a reasonable period of time. Many sales occur at prices other than what is considered the fair market value. The sale price is often adjusted due to the time constraints and pressures on the buyer and seller.


Certification for assessors varies across municipalities. In New York State, for example, a person becomes an assessor first by appointment or election. Then this person has to get a basic certification within three years of taking office, although assessors in some states are not required to obtain basic certification. The certification requires successful completion of orientation, which consists of three assessment administration course components and five appraisal components, including farm appraisal for certain agricultural communities. Appointed assessors are required to complete an average of 12 credits of continuing education annually.

Why Assessors Matter

Local municipalities base their property tax rates upon the value of owned property, including land. The assessments made by local assessors provide the basis for the municipality's calculation of property values. The local governing body uses the assessed tax to fund water and sewer improvements, provide law enforcement and fire service, K-12 and higher education, highway construction, and other services that benefit the community at large. Property tax rates and the types of properties taxed vary by jurisdiction, as does assessor certification.

Article Sources
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  1. Internal Revenue Service. "Publication 561 (02/2020), Determining the Value of Donated Property." Accessed Aug. 14, 2021.

  2. New York State Department of Taxation and Finance. "Assessors." Aug. 14, 2021.

  3. New York State Department of Taxation and Finance. "Certification Requirements—Assessors, Real Property Appraisers and Candidates." Accessed Aug. 14, 2021.

  4. New York State Department of Taxation and Finance. "Continuing Education Requirements." Accessed Aug. 14, 2021.

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