Your Property Taxes During a Decline-In-Market Value Cycle

​​California law, in part, requires that the assessed value of all assessable property is to be determined annually as of a specified value date, January 1, also known as the “lien date”.​ Even though annual bills come out in October each year, those bills are based on values as of the prior January 1. If the market value of a property on January 1 was less than the assessed value of the property on January 1, the assessor may temporarily reduce the assessed value to market value. For accuracy, market value appraisals are based on real estate market data for time periods as close to the date of value (January 1) as possible.​

The 2025/26 assessed values are available for review beginning July 1, 2025 and are based on values as of the prior January 1. ​Please review your assessed value closely and contact us with questions or concerns. The Assessor’s informal review filing period is July 1 – December 31. Formal appeals need to be filed with the Clerk of the Board of Supervisors​ by​ December 1st.

The temporary reduction discussed above is often referred to as a Prop 8 reduction (RTC​ 51​). Proposition 8 passed in November 1978, amending Proposition 13 to recognize declines in market value for property tax purposes. Once a Prop 8 reduced value has been enrolled, that property’s value must be reviewed each year and its assessed value will go up or down in tandem with its market value as of the January 1 of each year.

My Property Value has Declined

The review period is open.

Informal R​eview    

  • Taxpayers may request an informal review​ from the Assessor's Office between July 1​ and December 31*. There is no cost for this service. 
  • During the filing period you may file online​​ for an infor​mal review​​.​
  • Or you can print out a review ​request form​ and return it to our office. Review forms are not sent out by mail.
  • If this is a commercial property, submit a Commer​cial​​ ​​Addenda​​​​​​​​​​​​​ to expedite processing. 
  • An appraiser will review your property, make a determination, and our office will notify you of the results.
  • If the Assessor's Office determines a reduction is appropriate, a roll change will be processed.
  • If you disagree with the outcome of the review and the assessment appeal filing period is still open you may file an Assessment​ ​Appeal.

Requests for a Prop 8 Review and/or an Assessment Appeal may only be filed during their respective filing periods.

For more background and information on decline-in-market-value (Prop 8) and informal Assessor reviews, please see the reference pages below:

Recently Purchased Property: Sales Price Lower than Assessed Value

​ *If December 31 falls on a Saturday or Sunday​, mail postmarked on the next business day shall be deemed on time.