In California, property tax reassessment is the reset of your property’s taxable value to current market value, triggered when ownership changes hands or when you complete substantial new construction. Because Proposition 13 otherwise caps annual assessment growth at two percent, that reset often means a dramatic jump in the tax bill.1California State Board of Equalization. California Property Tax – An Overview Knowing which events trigger reassessment, and which ones qualify for an exclusion, can save a family hundreds of thousands of dollars over the life of ownership.
What Triggers a Reassessment
Revenue and Taxation Code Section 60 defines a change in ownership as a transfer of a present interest in real property where the recipient gets beneficial use and the value of the transferred interest is essentially equal to full ownership.2California Legislative Information. California Code Revenue and Taxation Code 60 – Change in Ownership The new owner must have the right to use the property now, not at some future date, and must receive the real economic benefits of ownership.
Outright sales are the most obvious trigger. If you sell your home for $900,000, that price becomes the new base year value, even if the prior owner was being taxed on a $250,000 assessment from decades earlier. The assessor typically checks the purchase price against recent comparable sales to set the new figure.
Long-term leases also trigger reassessment. Section 61 treats the creation, transfer, or termination of a lease with a term of 35 years or more, counting renewal options, the same as a change in ownership.3California Legislative Information. California Code Revenue and Taxation Code 61 Only the leased portion is reassessed. Homes on leased land that qualify for the homeowners’ exemption are conclusively presumed to have a renewal option of at least 35 years, so buying a home on a ground lease almost always resets the assessment on the improvement.
New Construction
Adding to or substantially altering real property counts as “new construction” under Section 70 and gets its own base year value assessment on top of the existing assessment for the rest of the property.4California State Board of Equalization. New Construction The definition is broader than most homeowners expect. It covers additions that increase square footage, converting a garage or unfinished basement into living space, rebuilding down to studs and foundation, upgrading plumbing or electrical capacity, and converting a single-family home into multiple units. Land improvements like grading, filling, terracing, and installing irrigation or storm drains also qualify.
Normal maintenance and repairs do not. Replacing a furnace, swapping galvanized pipes for copper, installing new carpet, painting, or replacing termite-damaged framing are treated as routine upkeep. The dividing line is whether the work makes the improvement the substantial equivalent of a new one. A full kitchen gut-renovation that changes the floor plan and upgrades all systems crosses that line; replacing countertops and appliances without structural changes does not.
If construction is only partly finished on the lien date of January 1, the assessor estimates the market value in its current state of completion, and that temporary assessment repeats each January 1 until the project is done. Once finished, the assessor sets a final base year value for the new construction, and the two-percent annual inflation cap runs from the following lien date.
One notable carve-out: active solar energy systems installed before January 1, 2027, are excluded from the new construction definition under Section 73. Rooftop solar panels and solar water heating (but not solar pool or hot tub heaters) do not increase your assessed value. The exclusion stays in place until the next change in ownership.
Transfers Between Spouses and Domestic Partners
Transfers between spouses do not trigger reassessment. Section 63 excludes all interspousal transfers, including transfers into a trust for a spouse’s benefit, transfers that take effect at death, transfers connected to a divorce or legal separation decree, and creating or terminating a co-ownership interest solely between spouses.5California Legislative Information. California Code Revenue and Taxation Code 63 If a divorce settlement awards one spouse the family home, the assessment stays put. The same is true when property is distributed from a legal entity to a spouse in exchange for that spouse’s interest in the entity as part of a divorce.
California extends the same protections to registered domestic partners. One partner can transfer property to the other, add or remove a partner from the deed, or distribute property through a trust at death without resetting the tax base. Even if the home’s market value has tripled since purchase, the existing base year value carries forward.
These exclusions cover all types of real property, not just a primary residence. Investment properties, vacation homes, and vacant land all qualify. The key requirement is that the relationship is legally established at the time of transfer. If you are relying on domestic partnership status, make sure the partnership is registered with the Secretary of State before the transfer is recorded. Miss that step and you can lose the exclusion entirely.
Parent-Child Transfers Under Proposition 19
Proposition 19, which took effect on February 16, 2021, dramatically narrowed the parent-child transfer exclusion. Under prior law, parents could pass a primary residence and up to $1 million in other real property to their children without reassessment. Today, the exclusion under Section 63.2 is limited to a family home, and only when the child actually moves in.6California State Board of Equalization. Proposition 19
To qualify, the property must be the transferring parent’s principal residence, and the child must make it their own principal residence and file for a homeowners’ exemption or disabled veterans’ exemption within one year of the transfer. If the child does not move in or misses the one-year deadline, the property is fully reassessed to current market value with no partial credit.
The Value Cap
Even when the child qualifies, there is a ceiling on the benefit. The exclusion covers only the difference between the factored base year value and a cap equal to that base year value plus $1,044,586 (the inflation-adjusted amount for transfers between February 16, 2025, and February 15, 2027). If market value at the time of transfer exceeds the cap, the excess is added to the base year value for the new assessment.
A concrete example. Suppose a parent’s home has a factored base year value of $500,000 and a current market value of $2,200,000. The cap is $500,000 plus $1,044,586, or $1,544,586. Market value exceeds the cap by $655,414. The child’s new taxable value becomes $500,000 plus $655,414, or $1,155,414. Still a meaningful benefit compared to a full reassessment at $2,200,000, but far less generous than the old rules.
The $1,044,586 figure is adjusted every two years based on the House Price Index published by the Federal Housing Finance Agency. Grandparent-to-grandchild transfers qualify for the same exclusion, but only if all parents of the grandchild who qualify as children of the grandparent are deceased at the time of transfer. Rental properties, vacation homes, and commercial real estate transferred to children no longer qualify for any exclusion under Proposition 19.
Joint Tenancy and Cotenancy Rules
Joint tenancy carries a right of survivorship: when one joint tenant dies, their share passes automatically to the survivors. Whether that transfer triggers reassessment depends on the “original transferor” concept in Section 65.7California Legislative Information. California Code Revenue and Taxation Code 65 – Change in Ownership of Joint Tenancy
An original transferor is someone who creates or transfers a joint tenancy interest and stays on the title afterward. As long as at least one original transferor remains on the title, no reassessment occurs. When the last original transferor leaves the title, the full property is reassessed. In practice: if a parent adds a child to the deed as a joint tenant, the parent is the original transferor. When the parent dies, the child receives the parent’s share, and reassessment is triggered because no original transferor remains.
A critical distinction applies to people who purchase property together as joint tenants from the start. Those buyers are transferees, not original transferors. If three family members buy a property together as joint tenants and one dies, the original transferor concept does not protect the survivors from reassessment of the deceased person’s share.
Proportional Interest Changes
Co-owners who change the way they hold title without changing their actual ownership percentages avoid reassessment under Section 62(a).8California Legislative Information. California Code Revenue and Taxation Code 62 Two people holding equal shares as tenants in common can switch to joint tenancy, or the reverse, without any tax consequence. The assessor looks at whether the economic interest actually changed, not the label on the deed.
Surviving Cotenant Exclusion
A separate exclusion under Section 62 protects surviving cotenants in specific circumstances. When one co-owner dies, the survivor may avoid reassessment if the two held 100 percent of the property between them, both lived in the home as their principal residence for at least one continuous year before the death, and the survivor held at least a 50-percent interest. This rule primarily helps unmarried partners and long-term housemates who would not qualify for the spousal exclusion. It does not apply where someone was added to the deed shortly before a co-owner passed away.
How Trusts Affect Reassessment
Transferring property into a revocable living trust does not trigger reassessment, provided the person setting up the trust remains the beneficiary or retains the power to revoke.9California State Board of Equalization. Property Tax Rule 462.160 – Change in Ownership – Trusts If you later dissolve the trust and transfer the property back to yourself, that is also not a change in ownership. That is why estate planners routinely use revocable trusts as the primary ownership vehicle in California without worrying about property tax consequences during the trust creator’s lifetime.
The reassessment risk arrives when a revocable trust becomes irrevocable, typically at the death of the person who created it. At that point, a change in ownership occurs unless the trust creator remains the sole present beneficiary or the transfer qualifies for another exclusion, such as the parent-child or spousal exclusion. Families using trusts to pass property to children need to make sure the transfer meets Proposition 19 requirements, or the property will be reassessed when the trust becomes irrevocable.
Legal Entity Ownership Changes
When property is held inside an LLC, corporation, or partnership, the assessor watches for ownership shifts at the entity level rather than on the deed. Section 64 creates two separate triggers.10California Legislative Information. California Code Revenue and Taxation Code 64
The first is a change in control. Reassessment occurs when any person or entity obtains direct or indirect control of more than 50 percent of the voting stock or majority ownership interest. If a corporation buys an LLC that owns an apartment complex, every property inside that LLC is reassessed even though no deed was recorded.
The second is a cumulative transfer of original co-owners’ interests. When property was originally transferred into an entity without reassessment (because the proportional interests stayed the same), the assessor tracks the original co-owners’ shares. Once more than 50 percent of those original interests have been transferred, all real property in the entity is reassessed as of the date the threshold was crossed.
All California real property held by the entity is subject to reassessment when either trigger is met. Business owners who structure deals as stock or membership interest purchases rather than asset purchases sometimes assume they have avoided reassessment. They have not. The entity-level rules exist to close that workaround.
BOE-100-B Filing Requirement
Legal entities must file Form BOE-100-B (Statement of Change in Control and Ownership of Legal Entities) with the Board of Equalization within 90 days of any change in control or ownership. This filing is required even if the entity believes an exclusion applies, and a separate Change in Ownership Statement filed with the county assessor does not substitute for it.11California State Board of Equalization. Legal Entity Ownership Program (LEOP) – Filing Requirements and Penalty Provisions The law does not allow extensions. If a property owner dies and the final distribution of entity interests is not yet determined, the entity must still file within 90 days of the death with whatever information is available and then amend the form once the distribution is finalized.
Missing the 90-day deadline triggers a 10-percent penalty. If a change in control or ownership did occur, the penalty is 10 percent of the taxes on the new base year value of all reassessed property. If no change occurred but the form was still required, the penalty is 10 percent of the current year’s taxes. The penalty can only be abated by filing an application with the county board of supervisors or assessment appeals board within 60 days of being notified by the assessor.
Transferring Your Tax Base to a New Home
Proposition 19 also created a benefit for homeowners who are at least 55 years old or severely and permanently disabled: the ability to transfer a low property tax base to a replacement home anywhere in California, up to three times. Before Proposition 19, a similar benefit was limited to moves within the same county (or to counties that had opted in) and could only be used once.
To qualify, the original home must be your principal residence eligible for the homeowners’ or disabled veterans’ exemption at the time of sale, and you must buy or complete construction of the replacement home within two years of selling the original. There is no minimum ownership or occupancy period, as long as it is your primary residence when you sell.
How the Value Adjustment Works
If the replacement home costs the same as or less than the original home’s market value, your old base year value transfers across with no adjustment. The definition of “equal or lesser value” depends on timing. If the replacement is purchased before the original is sold, the replacement’s market value must be 100 percent or less of the original’s. If purchased within the first year after the sale, up to 105 percent qualifies with no upward adjustment. In the second year after the sale, the threshold rises to 110 percent.
Buy a more expensive replacement above those thresholds and you still transfer your base year value, but the difference between the replacement’s market value and the original’s market value is added. For example, if your original home had a base year value of $300,000 and a market value of $600,000, and you buy a replacement within the first year for $700,000, your new taxable value is $300,000 plus the $100,000 difference, or $400,000.12California State Board of Equalization. Proposition 19 Fact Sheet Still dramatically lower than a $700,000 assessment.
Claims must be filed with the assessor of the county where the replacement home is located, using Form BOE-19-B (age 55 and older) or Forms BOE-19-D and BOE-19-DC (disabled persons). The filing deadline is three years from the date you purchase or complete construction of the replacement home.
Supplemental Tax Bills After a Reset
New owners are often caught off guard by supplemental tax bills that arrive separately from the regular annual bill. Whenever a change in ownership or completed new construction triggers reassessment, the county assessor determines the new market value and subtracts the prior assessed value. The resulting net increase (or decrease) is multiplied by the tax rate and prorated based on how many months remain in the fiscal year, which runs from July 1 through June 30.13California State Board of Equalization. Supplemental Assessment
The number of supplemental bills depends on when the transfer occurs. A transfer between June 1 and December 31 produces one supplemental bill covering the remainder of the current fiscal year. A transfer between January 1 and May 31 produces two: one for the remainder of the current fiscal year, and one for the entire following fiscal year beginning July 1.
Supplemental bills go directly to the property owner. Even if your mortgage lender pays your regular property taxes through an escrow account, the lender does not receive a copy of supplemental bills. Missing one is a common mistake for new California homeowners, and the penalties for late payment match those for regular property taxes.
Reporting Requirements and Penalties
Every property transfer requires paperwork with the county assessor, whether or not you believe an exclusion applies. The Preliminary Change of Ownership Report (PCOR) is filed when the deed is recorded with the county recorder. Skipping it triggers an additional $20 recording fee. The PCOR gives the assessor the information needed to determine whether the transfer qualifies for an exclusion.
For transfers that are not recorded, such as certain trust distributions or entity changes, the owner must file a Change in Ownership Statement within 90 days of the event. When a property owner dies, the personal representative or trustee has 150 days from the date of death to file.
If the assessor sends a written request for the Change in Ownership Statement and you fail to respond within 90 days, penalties apply. For property eligible for the homeowners’ exemption, the penalty is $100 or 10 percent of the taxes on the new base year value, whichever is greater, up to a maximum of $5,000 for non-willful failure. For property not eligible for the homeowners’ exemption, the cap rises to $20,000.14California Legislative Information. California Code Revenue and Taxation Code 482 These penalties are added to the tax roll and collected like delinquent property taxes.
Families claiming the parent-child exclusion under Proposition 19 must also file a specific claim form with the county assessor and ensure the child applies for the homeowners’ exemption within one year. The reporting burden falls on the transferee, and the assessor will not grant an exclusion it does not know about. Keep copies of every filed document. If an exclusion is later questioned during an audit, the burden of proof falls on the property owner.
Challenging a Reassessment
If you believe the assessor set your new base year value too high, or improperly denied an exclusion, you can file a formal assessment appeal. Each county has an assessment appeals board (or uses the county board of equalization for this purpose). The regular filing window opens on July 2 each year and closes on either September 15 or December 1, depending on whether the county assessor mailed assessment notices by August 1.15California State Board of Equalization. County Assessment Appeals Filing Period
For supplemental assessments specifically, you can file a separate appeal within 60 days of the supplemental tax bill’s mailing date. This shorter window catches many new owners by surprise, so mark the date as soon as the bill arrives. The appeal goes to the same county assessment appeals board. You do not need an attorney to present your case, but you should bring comparable sales data or an independent appraisal to support your claimed value.