Decline in Assessed Value


Decline in Value Assessment

COVID-19 Pandemic and your 2021-2022 Property Assessment

California property assessment rolls reflect economic conditions as of the date of a change in ownership, date of completion of new construction, or as of January 1 each year. If you request a decline review, we will estimate your property’s market value using income and expense data and sales occurring up to 90 days after January 1, 2021. If we find your property’s market value was less than its assessed value as of January 1, we will temporarily decrease the assessment and review its market value again the following year.

When an economic downturn occurs, it may affect the local real estate market causing housing and commercial values to drop. The law provides property tax relief to property owners if the value of their property falls below its assessed value.

Generally, property is assessed at the lesser of two values:

  1. Factored base year value (typically the purchase price adjusted annually for inflation, not to exceed 2% per year) or
  2. Current market value on January 1.

When the market value is the lesser value, the “Decline in Value Assessment Program” (Proposition 8) allows for a temporary reduction in assessed value.

If a property is enrolled in the Decline in Value Assessment Program, its assessed value is subject to annual review in subsequent years in light of current economic and market factors. For example, the assessed value may be:

  • increased to no more than the “factored base year value”, or
  • held at the prior year’s assessed value, or
  • reduced further.

Proposition 8 Assessed Value Increases Exceeding Two Percent (Restoration)

Some San Mateo County property owners whose properties were in the Decline in Value Assessment Program may see an increase (restoring to factored base year value) in their assessment values by more than two percent (2%).

Note: Although Proposition 13 expressly limits annual increases in a property’s “factored base year value” to no more than two percent per year, there is no such limitation on annual increases to a property’s assessed value in the Proposition 8 program, as long as the factored base year value is not exceeded.

Requesting a review:

The Assessor Division is now accepting new applications for the 2021-22 tax year. 

You may also submit your information by printing and mailing the following pdf form to our office.

Submit the request online PDF "Decline in Value" Reassessment Application Form

Decline in Value Application


(The market value must be lower than the current assessed value to qualify for reassessment.)

If you received a letter requesting additional information, please send the information to the e-mail provided in the letter, otherwise an appraiser will contact you if further information is needed.