You cannot fully avoid reassessment, but you can reduce the chance it happens

California's Proposition 13 locks your property tax rate at the value when you bought it, then increases it only 2% per year — unless the county assessor reassesses your property. A reassessment means the county looks at your home again and may raise the taxable value, which raises your tax bill. You cannot stop the county from reassessing if they have legal cause, but you can avoid the most common triggers: selling the property, making major improvements, or filing certain documents that alert the assessor to changes.

The reassessment happens automatically when you transfer ownership, so if you own the home outright and do not sell, you have already avoided the biggest trigger. The second-largest trigger is visible construction — a new roof, addition, or major renovation that the assessor notices during a routine inspection or that you report to the county for a building permit. The third is paperwork: refinancing, taking out a home equity line of credit, or recording a deed of trust can flag your property for review, though not all of these trigger reassessment.

Key Takeaways

  • A change in ownership — including inheritance, transfer to a trust, or sale — triggers reassessment in most cases, even if the property stays in the family.
  • Visible construction, especially additions or structural changes, prompts the assessor to inspect and may raise your assessed value.
  • Refinancing your mortgage or taking out a home equity line of credit does not automatically trigger reassessment, but recording certain documents can alert the assessor to inspect.
  • The county assessor can reassess at any time if they believe the value has changed materially, regardless of whether you took action.
  • Contesting a reassessment through the Assessor's Parcel Number (APN) appeal process is your main recourse if the new value seems wrong.

When the county must reassess your property

The county is required to reassess when there is a change in ownership. In California, this includes a sale to anyone, a transfer to a family member, a transfer into a living trust, or an inheritance — even if the property stays in the family and the value has not changed. The only major exception is a transfer between spouses or from a parent to a child under Proposition 19, which has strict conditions and requires filing a claim with the assessor within three years of the transfer.

If you inherit a home or receive it as a gift from a parent, you can file a Claim for Reassessment Exclusion (Form BOE 58-H) to keep the old assessed value, but you must do so within three years. If you miss the deadline, the property reassesses at current market value. A transfer into a revocable living trust during your lifetime does not trigger reassessment if you are the sole beneficiary, but a transfer after your death does — unless the heir files the claim in time.

The county also must reassess if you file a formal notice of completion for a building permit or if the assessor's office receives a report of new construction. This includes major additions, new structures, or structural changes that increase the usable square footage or change the property type.

Construction and improvements that trigger inspection

Any work that requires a building permit — a second story, a new garage, a deck over a certain size, or a room addition — will likely trigger reassessment once the permit is closed out. The county assessor receives notice from the building department and will inspect the property to measure the new square footage and update the property record. Even if you do not file for a permit, the assessor can discover the work during a routine inspection or from a neighbor's report and reassess based on what they observe.

Work that does not require a permit — interior remodeling, painting, flooring, or mechanical upgrades — does not automatically trigger reassessment. However, if the work is visible from outside or if the assessor inspects for any reason and sees major improvements, they may reassess. The safest approach is to assume that any visible change to the exterior or footprint of the home could prompt a reassessment.

Routine maintenance — roof repair, siding replacement, or HVAC replacement — does not trigger reassessment as long as you are not expanding the home or changing its character. The assessor is looking for changes in value, not upkeep.

Refinancing and financial documents that may flag your property

Refinancing your mortgage does not automatically trigger reassessment. The county does not monitor loan activity, and a new loan against the same property is not a change in ownership. However, some counties have programs where they cross-reference property sales data with loan records, so if a refinance is recorded as a sale or transfer, it could alert the assessor.

A home equity line of credit (HELOC) or a home equity loan also does not trigger reassessment on its own — these are liens against the property, not transfers of ownership. Recording a deed of trust (the security document for the loan) is a normal part of the lending process and does not change ownership.

The risk comes if you record a document that the assessor interprets as a change in ownership or if you file paperwork that includes language suggesting a transfer. For example, if you add a spouse's name to the deed, that may be flagged as a transfer and require you to file an exemption claim. If you are unsure whether a financial transaction will trigger reassessment, contact your county assessor's office before signing — they can tell you whether the specific document will flag your property.

How to reduce the risk of reassessment

The most direct way to avoid reassessment is to not sell the property and to not make visible improvements. If you must refinance, do so without changing the deed or ownership structure. If you need to add a family member to the title, ask your lender and the county assessor whether it will trigger reassessment before you proceed — in some cases, you can add a spouse without triggering it under community property rules, but this varies by situation.

If you are planning construction, understand that a building permit is a public record and will reach the assessor. You cannot hide it. However, you can minimize the scope: work that does not require a permit will not automatically alert the assessor, though visible changes still carry risk. If you are doing major work, accept that reassessment is likely and budget for a higher tax bill.

If you own the property in a trust or are considering putting it into one, do so before you sell or transfer it. A transfer into a revocable living trust during your lifetime does not trigger reassessment if you remain the sole beneficiary and the trustee. This is a common estate planning move that preserves your Proposition 13 protection.

What to do if your property is reassessed

Once the county assessor issues a new assessed value, you have the right to contest it. The process is called an Assessor's Parcel Number (APN) appeal or a Proposition 15 appeal, and it is free. You do not need a lawyer, though you can hire one if you choose.

The first step is to file a Notice of Disagreement with your county assessor within 30 days of receiving the reassessment notice. The form is available on the assessor's website. In the notice, you explain why you believe the new value is wrong — for example, the square footage is incorrect, comparable homes in your area sold for less, or the condition assessment is inaccurate.

If the assessor does not lower the value after your initial protest, you can request a hearing before the Assessment Appeals Board, which is an independent county body. You will present evidence — comparable sales, photos, inspection reports — to show that the assessed value is too high. The hearing is informal and you can present your case yourself. If you lose at the Appeals Board level, you can file a lawsuit in Superior Court, though this is rare and expensive.

Transfers to family members and trusts

If you inherit a home or receive one as a gift from a parent, you can file a Claim for Reassessment Exclusion (Form BOE 58-H) to keep the property at its old assessed value. You must file within three years of the transfer. The claim works only if the property is a single-family home, a condo, or a mobile home, and only for transfers from parent to child or between spouses.

If you transfer the property into a revocable living trust while you are alive and you are the sole beneficiary, no reassessment occurs. This is one of the few ways to restructure ownership without triggering Proposition 13 reset. However, if the trust becomes irrevocable or if someone other than you becomes a beneficiary, reassessment may occur.

If you are considering any ownership change — adding a family member, creating a trust, or transferring to a business entity — contact your county assessor before you do it. They can tell you whether the specific change will trigger reassessment and what forms you need to file to preserve your protection.

Frequently Asked Questions

Does adding my spouse to the deed trigger reassessment?

Not always. If you are married and the property is community property, adding your spouse's name may not trigger reassessment, but it depends on your county and how the deed is recorded. Contact your assessor before adding a name to the deed. If it does trigger reassessment, you may be able to file an exemption claim.

If I do major renovations without a permit, will the assessor find out?

Possibly. The assessor conducts routine inspections and can see visible changes from outside. Neighbors can also report new construction. If the assessor discovers unpermitted work, they can reassess based on what they observe. Unpermitted work also creates legal and insurance problems beyond the tax issue.

Can I appeal a reassessment if I think the new value is wrong?

Yes. File a Notice of Disagreement with your county assessor within 30 days of the reassessment notice. If the assessor does not lower the value, you can request a hearing before the Assessment Appeals Board. You can present evidence like comparable sales or inspection reports to challenge the value.

What happens if I transfer my property into a living trust?

A transfer into a revocable living trust during your lifetime does not trigger reassessment if you are the sole beneficiary and trustee. This is a common way to avoid probate while keeping your Proposition 13 protection. After your death, the property reassesses unless the heir files a Claim for Reassessment Exclusion within three years.

Does refinancing my mortgage trigger reassessment?

No. Refinancing is a loan transaction, not a change in ownership, so it does not trigger reassessment. However, make sure the lender does not record the refinance as a transfer or sale. If you are unsure, ask your lender and assessor before signing the loan documents.