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Governor-Declared Disaster

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Voters passed Proposition 19 in November 2020. This legislation affects Parent-Child and Grandparent-Grandchild exclusions and Base Year Value Transfers. This legislation is currently being reviewed by the State Board of Equalization (BOE) for guidance and regulations. The Assessor’s Office will not be able to answer detailed questions about the legislation at this point in time. Visit the BOE’s Proposition 19 page for the most up to date information. 

Fire-Affected Property Notice of Corrections

Property owners with real property that was destroyed or suffered damage over $10,000 as a result of the recent fires will start receiving fire damage reassessment notices over the next few weeks. Please see our FAQs for more information.


If your property has been substantially damaged or destroyed in a Governor-proclaimed disaster and you have filed a disaster relief claim with the county assessor to reduce your taxes, or the assessor has initiated the reassessment without a claim form, you may rebuild in a like or similar manner and your previous base year value (Proposition 13) will be reinstated. Or, you may choose to buy another comparable property and transfer your base year value to the new property. You will not be able to do both.

There are two different types of base year value transfers for properties damaged in a Governor-proclaimed disaster and each has different requirements:

  1. Proposition 50 – intra county transfers (within Sonoma County)
  2. Proposition 171 – inter county transfers (outside of Sonoma County)

Governor must proclaim a state of emergency for the disaster, typically: wildfire, earthquake, winter storms, flood, gas explosion (San Mateo County), freeze, civil disorder.

State Board of Equalization Governor-Declared Disaster list

Proposition 50

About Proposition 50

Proposition 50 allows property owners to transfer the base year value of the original property that has been substantially damaged or destroyed by a disaster to comparable property located in the same county. 


  • Must be a Governor proclaimed disaster
  • Both properties must be located within the same county
  • Allows Any type of real property
  • Replacement property must be similar in size, utility and functions
  • Acquired within 5 years - real property must be purchased or newly constructed
  • The type of ownership is not limited – can include legal entities

Please see Revenue & Taxation Code section 69 for all of the requirements.

Proposition 171

About Proposition 171

Proposition 171 allows for a base year value transfers from a principal residence that is damaged or destroyed in a Governor-declared disaster to another county.


  • Must be a Governor Proclaimed disaster
  • Inter county transfers – receiving county must have ordinance (Sonoma County has this ordinance)
    Check for counties that have passed an ordinance (question #2)
  • Limited to principal places of residence
  • Replacement home must be equal or lesser value
  • Acquired within 3 years
  • Only individuals are eligible –  property owned by legal entity is ineligible
  • Claim must be timely filed

A claim must be filed within 3 years of the date of purchase or completion of new construction.

Please see Revenue & Taxation Code section 69.3 for all of the requirements