You cannot fully avoid reassessment, but you can prevent the events that trigger it

California reassesses your property when you sell it, transfer ownership, or make certain improvements — not based on market value changes alone. The county assessor's office will reassess after a change in ownership or new construction. You cannot stop the assessor from doing their job, but you can avoid the specific transactions and renovations that cause reassessment to happen in the first place.

If reassessment has already occurred, you have the right to file a Proposition 8 claim (a decline-in-value appeal) or a Proposition 13 base year value appeal if the assessment was incorrect. These are different from preventing reassessment — they challenge the assessed value after the fact.

Key Takeaways

  • Reassessment happens automatically when you sell the property, transfer it to someone else, or complete new construction or major improvements.
  • Keeping the property in your name and avoiding major renovations are the main ways to delay reassessment, but they do not prevent it permanently.
  • Certain transfers between family members may may have access to for a parent-child exclusion under Proposition 193, which can defer reassessment in some cases.
  • If your property was reassessed and you believe the new value is too high, you can file a Proposition 8 appeal based on current market conditions.
  • The assessor must reassess within 60 days of a change in ownership; you will receive a notice in the mail when this happens.

What counts as a change in ownership that triggers reassessment

The county assessor reassesses your property whenever ownership changes. This includes a sale to a buyer, a gift to a family member, a transfer into a trust, or adding someone's name to the deed. Even if you keep living in the house and nothing physical changes, the reassessment happens because the assessor's records show a different owner.

The assessor uses the transfer document (the grant deed or other recorded instrument) as the trigger. Within 60 days of recording, the assessor's office will send you a Notice of Reassessment or a Preliminary Change of Ownership Report (PCOR). This notice tells you the new assessed value. You do not have to do anything to make reassessment happen — it is automatic once the deed is recorded.

Some transfers do not trigger reassessment. These include transfers between spouses, transfers from a parent to a child (under Proposition 193), transfers between domestic partners, and transfers to a revocable living trust if you are the trustor and the property is your principal residence. Each of these has specific rules and documentation requirements.

How new construction and major improvements cause reassessment

The assessor also reassesses when you add new construction to the property. This means any structure that increases the property's value — a new house, an addition, a garage, a pool, or a permanent deck. The assessor will add the value of the new construction to your base year value, even if you do not sell the property.

Not every home improvement triggers reassessment. Repairs and replacements (fixing a roof, replacing windows, painting) do not count as new construction. The line between repair and improvement is sometimes unclear. If you replace a roof with the same materials and design, that is a repair. If you add insulation or change the roof pitch, that may be treated as an improvement. The assessor makes this information, and you can dispute it.

Unpermitted work can also trigger reassessment. If the assessor discovers construction you did not report to the county, they may reassess the property and potentially assess penalties. Permitted work is recorded in the county's system, so the assessor knows about it. Unpermitted work may go unnoticed for years, but if discovered during a sale, refinance, or routine inspection, it can lead to reassessment and back taxes.

The parent-child property transfer exclusion under Proposition 193

If you inherit property from a parent or transfer property to a child, you may be able to exclude the transfer from reassessment under Proposition 193. This exclusion applies only to the first $1 million of the property's value (adjusted annually for inflation; the 2024 limit is approximately $1.3 million). The exclusion applies to the parent's principal residence and up to one acre of other property.

To use this exclusion, you must file a Claim for Parent-Child Exclusion with the assessor within three years of the transfer. The form is available from your county assessor's office. You will need to prove the relationship (a birth certificate or marriage certificate) and show that the property qualifies. If you miss the three-year important date, you lose the exclusion and the property will be reassessed at current market value.

The exclusion does not prevent reassessment entirely — it just keeps the assessed value at the parent's base year value for the excluded portion. Any value above the exclusion limit is reassessed. If the property is worth $2 million and the exclusion limit is $1.3 million, the assessor will reassess the top $700,000.

Transfers into a revocable living trust and reassessment

Transferring property into a revocable living trust does not trigger reassessment if you are the trustor (the person who created the trust) and the property is your principal residence. The assessor treats this as a non-change of ownership because you still control the property in the same way.

If you transfer property into a trust and you are not the trustor, or if the property is not your principal residence, reassessment will happen. Similarly, if the trust becomes irrevocable (which usually happens after your death), the property may be reassessed when it transfers to the beneficiaries. The rules depend on the type of trust and who receives the property.

You must file a Preliminary Change of Ownership Report (PCOR) with the county recorder when you transfer property into a trust, even if reassessment does not explore. The form asks whether the transfer is a change of ownership. If you check "no" and the assessor disagrees, you may face penalties. If you are unsure, contact your county assessor before filing.

Challenging a reassessment through a Proposition 8 appeal

If your property was reassessed and you believe the new value is too high, you can file a Proposition 8 claim (also called a decline-in-value appeal). This appeal is based on the current market value of the property, not on the previous assessed value. You use it when the property's market value has dropped below the assessed value.

To file a Proposition 8 claim, you must submit a form to your county assessor within 30 days of receiving the reassessment notice, or by the assessment roll's lien date (usually August 10), whichever is later. The form is called the process for Reduction in Assessed Value. You will need to provide evidence of the property's current market value — comparable sales, an appraisal, or a real estate agent's opinion of value.

The assessor will review your claim and either reduce the value or deny it. If you disagree with the decision, you can appeal to the Assessment Appeals Board in your county. This is a free process. You do not need a lawyer, though you can hire one if you choose. The board will hold a hearing and make a final decision.

Keeping property in your name versus transferring ownership

The simplest way to avoid reassessment is to keep the property in your name and not transfer it to anyone else. As long as you own it and do not sell it, the assessed value stays at the base year value (adjusted annually for inflation, up to 2 percent per year under Proposition 13). This can save you money over decades if the property's market value rises faster than 2 percent per year.

If you want to pass the property to your heirs without triggering reassessment, you have limited options. A revocable living trust can work if you are the trustor and the property is your principal residence. A parent-child transfer can work if you file the exclusion claim on time. For other situations — transferring to a spouse, a domestic partner, or a non-principal-residence property — reassessment will happen, but you may be able to time it strategically.

Some people delay selling a property specifically to avoid reassessment, because they know the assessed value will jump to market value. This is a personal financial decision that depends on your tax situation, your plans for the property, and the difference between the current assessed value and the market value.

Frequently Asked Questions

If I add a room to my house, will my property taxes go up when ready?

Yes, but not until the assessor knows about it. If you pull a permit, the county records it and the assessor will reassess within a few months. If you do unpermitted work, the assessor may not know until years later — but when they do, you will owe back taxes plus penalties. It is safer to permit the work.

Can I avoid reassessment by putting the property in my child's name while I am still alive?

No. Adding your child's name to the deed is a change of ownership and triggers reassessment. The parent-child exclusion only applies if you transfer the property after you die or if you meet specific conditions for a lifetime transfer. Check with your county assessor about whether your situation qualifies.

What happens if I transfer property to my spouse?

Transfers between spouses do not trigger reassessment. The assessor treats this as a non-change of ownership. You must file a Preliminary Change of Ownership Report and indicate that it is a spousal transfer. After a divorce, the property may be reassessed if it transfers to the ex-spouse, depending on the timing and the court order.

How often can I file a Proposition 8 appeal?

You can file a new Proposition 8 claim each year if the property's market value continues to decline. Each claim must be filed within 30 days of receiving the reassessment notice or by the lien date, whichever is later. Once the market value rises above the assessed value, you cannot file a Proposition 8 claim anymore.

If I refinance my mortgage, will my property be reassessed?

No. Refinancing does not change ownership, so it does not trigger reassessment. The lender may require an appraisal, but that appraisal does not affect your property tax assessment. Only a change in ownership or new construction triggers reassessment.