California Disaster Property Tax Reassessment

Last reviewed: May 16, 2026. This guide uses official California and county sources available on that date. Disaster rules, county forms, and filing periods can change after fires, storms, and emergency declarations.

What California calamity reassessment does

California Revenue and Taxation Code section 170 allows counties to reassess taxable property that was damaged or destroyed by a misfortune or calamity, if the damage happened without the fault of the person assessed or the person liable for the taxes.

The California State Board of Equalization says this relief can apply to disasters such as fire, earthquake, or flooding. The county assessor reappraises the property to reflect its damaged condition. All California counties have adopted an ordinance for this type of disaster relief, according to the Board of Equalization’s disaster relief page.

In plain English, this means the assessor may temporarily lower the taxable value while the property is damaged. Property taxes are then adjusted based on that lower value for the period allowed by law.

This does not mean the county pays for repairs. It does not replace insurance. It does not decide whether the home is safe to occupy. It only deals with property tax assessment.

The damage threshold matters

For the basic section 170 calamity reassessment, the estimated loss must be at least $10,000 of current market value. This figure appears in the state rule and on many county assessor pages.

The loss is not always the same as your repair bill. The assessor looks at how the damage reduced the taxable property’s value. A large repair bill may support your claim, but the assessor still makes a value decision.

The law can cover more than a house. The Board of Equalization says disaster reassessment may be available for owners of real property, business equipment and fixtures, orchards or other agricultural groves, aircraft, boats, and certain manufactured homes.

It generally does not cover property that is not assessed for local property tax. Household furnishings are a common example. State-licensed manufactured homes can also be outside this reassessment path because they may not be assessed by the county assessor in the same way.

What kinds of damage may qualify

Common examples include wildfire damage, flood damage, earthquake damage, storm damage, mudslide damage, and other sudden calamities.

The event does not always have to be a Governor-proclaimed disaster for basic section 170 reassessment, but a Governor proclamation can matter for other relief, including certain tax installment deferrals and base-year value transfer rules.

Normal aging, deferred maintenance, construction defects, or slow deterioration may be treated differently. For example, San Diego County states that damage from a falling tree or heavy winds may qualify if it meets the damage threshold, but a roof leak caused by age and normal deterioration may not. Sacramento County gives similar cautions on its calamity claim page.

If you are unsure whether the damage counts as a calamity, file or contact the county assessor quickly. Waiting can create a deadline problem.

Where to file in California

You file with the county assessor for the county where the damaged property is located. The state does not use one single form for every county.

The Board of Equalization says the form and title differ from county to county. Some counties call it an application for reassessment of property damaged or destroyed by misfortune or calamity. Others call it a calamity claim or disaster relief claim.

You can find official assessor contacts through the Board of Equalization’s county contacts list. Use the assessor, not a private tax appeal company, as the starting point for the official claim.

Examples of county filing pages

These examples show why county checking matters:

• Los Angeles County: The Assessor describes misfortune and calamity tax relief and identifies its application as Form ADS-820 on the county disaster relief page.
• San Diego County: The Assessor/Recorder/County Clerk provides an online disaster relief application page and lists examples of supporting documents.
• Sacramento County: The Assessor explains calamity claims, tax installment deferral, and several filing cautions on its flood, fire, or disaster page.
• Ventura County: The Assessor explains temporary reduced assessment and rebuilding rules on its disaster relief page.

These are examples only. Use your own county’s current form and instructions.

Documents to gather before you file

You do not need a perfect file before contacting the assessor. But you should gather as much proof as you can. The goal is to show what happened, when it happened, what was damaged, and how the damage affected value.

• Assessor parcel number, property address, and owner name.
• Date of the disaster or damage.
• Photos and video of the damage before cleanup, if available.
• Fire department report, building department notice, emergency order, insurance report, or other official damage report.
• Insurance claim information, if you filed a claim.
• Contractor estimates, repair contracts, engineering reports, or invoices.
• Permit records for demolition, repair, or rebuilding.
• A short written description of what was damaged.
• Any notice from the county, city, Cal Fire, emergency management office, or code enforcement office.
• Your current property tax bill and any supplemental tax bills.

San Diego County specifically lists official damage reports, photographs, and contractor estimates or repair contracts as useful documentation. Other counties may ask for similar proof, but the form and upload method can differ.

How the assessor usually reviews the claim

After you file, the assessor reviews the application and may ask for more information. The assessor may inspect the property, use your documents, compare before-and-after facts, and review the property record.

Under section 170, the assessor determines the full cash value of the land, improvements, and taxable personal property immediately before and after the damage or destruction. If the before-and-after loss meets the legal threshold, the assessor calculates a percentage reduction.

That percentage is then used to reduce the values on the assessment roll. The tax adjustment is prorated. In practice, this means the reduction usually applies for the period the property is in damaged condition, not forever.

Ventura County explains that the temporary reduction runs from the month the disaster occurred until the property is rebuilt or repaired, with annual review for progress. San Diego County describes a temporary prorated value reduction that remains in effect from the first day of the month in which damage occurred to the last day of the month in which repairs are completed.

Keep paying attention to the tax bill

A disaster reassessment claim and a tax bill are connected, but they are not the same thing.

The Board of Equalization says that after the assessor processes an application, a notice of proposed new assessment is sent. A separate supplemental refund may be issued if taxes were already paid, and the owner does not have to file a separate refund claim for that refund. But the Board also cautions that the regular tax bill still must be paid.

This is important. If you ignore a property tax bill while waiting for the assessor, penalties may still become a problem unless an official deferral or other county-approved payment rule applies.

Disaster tax installment deferral is separate

California has a separate disaster tax installment deferral chapter in Revenue and Taxation Code sections 194 through 196.99. This can matter when the property is in a Governor-proclaimed emergency area and the owner files a qualifying reassessment claim.

Under section 194.1, a timely deferral claim may defer the next regular secured property tax installment without penalty or interest until the assessor reassesses the property and a corrected bill is sent, or until the assessor determines the property is not eligible and gives notice. After the new due date, unpaid taxes can become delinquent and penalties can apply.

There are limits. Section 194.1 says the deferral does not apply to property taxes paid through impound accounts. Sacramento County also states that the tax collector processes the actual deferral and that the deferral application must be filed with the calamity claim before the next current-year payment is due.

Do not assume a deferral applies just because your property was damaged. Ask your county assessor and tax collector what forms are required and whether your bill, payment method, and disaster event qualify.

Rebuilding can affect the assessment

If your property is rebuilt in a like or similar manner, California’s disaster relief rules generally allow the prior Proposition 13 base-year value to be retained for tax purposes. This is one reason it is important to file the calamity reassessment claim and keep repair records.

Like or similar does not always mean identical. But major additions or upgrades can create a new construction assessment for the added value. Ventura County explains that if rebuilt property goes beyond the destroyed property’s substantially equivalent size, utility, or function, the extra portion may be assessed at market value.

If your property was substantially damaged or destroyed in a Governor-proclaimed disaster, other options may also exist. The Board of Equalization explains that there are base-year value transfer rules for certain replacement properties. Proposition 19 also allows some owners whose primary residence was substantially damaged or destroyed by wildfire or Governor-proclaimed natural disaster to transfer taxable value to a replacement primary residence in California, if the legal requirements are met.

This is a more complicated area. If you plan to rebuild, sell, or buy replacement property, ask the assessor which path applies before you make assumptions. The Board of Equalization notes that an owner may choose to rebuild and retain the prior value or buy another comparable property and transfer the base-year value, but not do both for the same loss.

If the property record looks wrong after the disaster

Many homeowners notice a problem because the county record still shows a full house, a full garage, or improvements that were destroyed or partly removed. Others see a permit or repair recorded in a way that does not match what happened.

If this happens, ask the assessor for the property record or assessment details. Then compare it with your damage evidence.

• Does the record still show a structure that was destroyed?
• Does the square footage match the property after the damage?
• Does the assessor know the date of damage?
• Does the record separate land, improvements, and taxable personal property correctly?
• Did the assessor treat a repair as new construction?
• Did the county miss a demolition permit, red tag, fire report, or insurance report?

Send the assessor clear evidence. Use dates. Label photos. Keep copies of every form and message. If you speak by phone, write down the date, the office, and the name or title of the person you spoke with.

Calamity reassessment is not the same as an exemption, rebate, freeze, or appeal

Property tax terms can sound alike. They do different things.

If the assessor denies the claim or the value still looks too high

The assessor should notify you in writing of the proposed reassessment. Under section 170, that notice must state that the applicant may appeal the proposed reassessment to the county board within six months from the date the notice was mailed.

An appeal is about evidence. It is not about how stressful the disaster was, even though the stress is real. Focus on facts:

• before-and-after property condition;
• photos and official damage reports;
• contractor estimates and engineering reports;
• insurance scope of loss;
• demolition, repair, and permit records;
• market evidence, if the dispute is about value;
• proof that the claim was filed on time.

If the problem is not the disaster reassessment but the regular assessed value, the normal assessment appeal deadline may be different. Use the county’s assessment appeals board or clerk of the board instructions for the correct process.

If you are late

Contact the county assessor anyway. Explain the date of damage, the reason you are late, and whether you received any notice or application from the assessor.

Do not assume the county can accept a late claim. The law and county ordinance control. But the assessor can tell you whether a special disaster rule, a county ordinance period, a county-initiated application, or a recent statutory extension applies.

If you are also behind on the tax bill, contact the county tax collector. The assessor handles value. The tax collector handles billing, due dates, penalties, payment status, and collections. If you have received a lien, tax sale, or foreclosure warning, consider contacting legal aid or a qualified professional quickly.

A simple filing plan for homeowners

Official sources to check

For statewide rules, start with the Board of Equalization’s California disaster relief page. It explains section 170 reassessment, base-year value transfer concepts, county filing, and the $10,000 loss threshold.

To check whether a disaster was Governor-proclaimed for property tax purposes, use the Board of Equalization’s Governor-proclaimed disaster list.

To find the correct local office, use the Board of Equalization’s county assessor and tax collector contacts. Your assessor’s current page and form should control the filing details for your county.