Prop 13 and Prop 19 for Foothill Homeowners Who Move

If you have lived in your foothill home for a long time, there is a good chance your property tax bill is a lot lower than a new neighbor’s bill. That gap is not luck. It comes from California’s property tax rules, and those rules matter a great deal the moment you think about selling, downsizing, or passing a home to your kids.

I get these questions all the time from longtime owners: “If I sell, will my taxes jump?” “Can I take my tax value with me?” “What happens if my children inherit the house?” This guide walks through what the State Board of Equalization (BOE) and the LA County offices say about each one, in plain words, with links to the sources so you can read them yourself.

One important note before we start. I am a REALTOR(R), not a tax professional or an attorney. Everything here is general information drawn from public agencies. Your situation has details that this guide cannot see, so please run your own numbers past a California CPA or attorney and the County Assessor before you decide anything.

The short version

• Proposition 13 (1978) limits how fast the taxable value of your home can grow while you own it. It resets to market value when ownership changes or when new construction is completed.
• Proposition 19 (approved November 3, 2020) lets homeowners who are age 55 or older, who are severely and permanently disabled, or who are victims of a wildfire or natural disaster carry their existing taxable value to a replacement home anywhere in California, up to three times, with conditions.
• Prop 19 also narrowed the parent-child and grandparent-grandchild exclusions. A family home now has to become the new owner’s primary residence, and there is a value cap.
• Two LA County tax bills arrive each year, with fixed due dates. A purchase or new construction can also trigger an additional supplemental bill.

The rest of this guide explains each piece, then lists the questions I would bring to a CPA or attorney.

Prop 13 in plain language

The BOE describes Proposition 13 as a property tax limitation measure that limited the property tax rate to one percent plus the rate needed to pay for local voter-approved bonds, and capped annual increases in a property’s assessment at no more than two percent. It also changed the system from one based on current market value to one based on the value when the property was acquired.

Here are the terms you will see over and over.

Base year value. When you buy a home, or when new construction is finished, the County Assessor establishes a base year value, which generally follows the sales price.

Factored base year value (FBYV). Each year the base year value is adjusted by an inflation factor based on the California Consumer Price Index, not to exceed two percent. The BOE publishes the factor each year in a Letter to Assessors, and county assessors use it to prepare the assessment roll.

Assessed value. This is the dollar value the Assessor assigns for tax purposes. In most years it is the lower of the factored base year value or the market value.

Market value. What the property would bring if offered for sale on the open market. Over many years it can climb well past the assessed value.

The BOE gives a simple illustration in its information sheet: a home bought for $400,000 in May 2015 has a factored base year value of about $471,300 for the 2024 tax year. If its market value on January 1, 2024 is $750,000, the Assessor still cannot assess it above $471,300. That is why two similar houses on the same street can carry very different tax bills if one was bought many years before the other. The BOE uses its own example of a 2014 purchase and a 2022 purchase to make the same point.

What triggers a reassessment

According to the BOE, a property is reassessed to market value when there is a change in ownership or when new construction is completed, unless an exclusion applies.

• A change in ownership is a transfer of a present interest in the property that is substantially equal in value to a fee interest. The BOE’s examples: a purchase or an inheritance.
• New construction includes building a new house on vacant land, and also additions such as a new bedroom or a pool. For an addition, only the new portion is assessed at market value as of completion, and the rest of the property is not reassessed.

The temporary decline-in-value rule

Prop 13 is not only a one-way ratchet. The BOE explains that under Proposition 8 (1978), if market value on January 1 falls below the factored base year value, the Assessor enrolls the lower market value for that year. Once the market recovers, the value cannot go above the factored base year value without a change in ownership or new construction. If you believe your market value is below your assessed value, the BOE says you can contact the County Assessor for an informal review.

Who does what

The BOE explains that the Assessor values the property and applies exemptions, the Auditor-Controller computes the tax, and the Tax Collector mails and collects the bill. Questions about value go to the Assessor; questions about payment go to the Tax Collector.

If the home is your principal residence, the BOE says you are entitled to the Homeowners’ Exemption, which reduces the assessed value by $7,000. Qualifying veterans and their unmarried surviving spouses may qualify for the Disabled Veterans’ Exemption (Revenue and Taxation Code section 205.5), which is a separate and larger exemption.

What Proposition 19 changed

Proposition 19 passed on November 3, 2020, and its implementing legislation (Senate Bill 539) was enacted on September 30, 2021. The BOE’s summary says it did two main things:

1. It added a new base year value transfer for primary residences, for people who are at least age 55, who are severely and permanently disabled, or who are victims of a wildfire or natural disaster.
2. It changed the parent-child and grandparent-grandchild exclusions.

The BOE lists the operative dates: the intergenerational changes began February 16, 2021, and the base year value transfers began April 1, 2021. Transfers through February 15, 2021 fall under the older Proposition 58/193 rules.

Taking your taxable value with you: the base year value transfer

This is the piece most longtime foothill owners ask about. Here is what the BOE’s fact sheet (Publication 801, updated June 2025) says.

Who can use it. A homeowner who is age 55 or older, or who is severely and permanently disabled of any age, may transfer the taxable value of their principal residence to a replacement property. The BOE says the replacement can be anywhere in California, and that the transfer can be used up to three times. Before Prop 19, the BOE notes, the older rules were narrower: the replacement home had to be in the same county or an eligible intercounty location, and the transfer could be used once.

The main conditions. From the fact sheet:

• The replacement residence must be purchased or newly constructed within two years of the sale of the original property.
• At the time the original property is sold, the claimant must be age 55 or older, or severely and permanently disabled of any age.
• Both the original and replacement properties must be eligible for the homeowners’ or disabled veterans’ exemption. The claimant must own and live in the original property when it sells.
• Either the sale of the original or the purchase or completion of the replacement must happen on or after April 1, 2021.
• The original must be sold, and the replacement purchased, “for consideration,” meaning something of value such as cash, creation or cancellation of debt, or exchange of other property.

How the new taxable value is figured. The BOE says there is no limit on the market value of the replacement compared to the original. However, the amount above the original’s market value gets added to the transferred value. Its two examples:

• If the original’s taxable value is $300,000 and its market value is $900,000, and the replacement’s market value is $700,000, the taxable value transferred stays at $300,000.
• If the original’s taxable value is $300,000 and its market value is $600,000, and the replacement’s market value is $700,000, the $100,000 difference is added, so the replacement’s taxable value is $400,000.

There is a timing wrinkle. The BOE fact sheet says the replacement’s market value can exceed the original’s by up to 105 percent if the replacement is purchased within the first year after the original sells, or 110 percent in the second year, with no excess added to the transferred value. It also notes that the plain “difference is added” example assumes the replacement is purchased before the original. If the replacement is purchased after the original, the amount over 105 or 110 percent is what gets added. These details are exactly the kind that make a CPA or the Assessor’s office worth a call before you sign anything.

Wildfire and natural disaster victims. The BOE says victims of a wildfire or Governor-declared disaster can transfer the taxable value of their primary residence anywhere in the state under the same conditions as the age 55 claim, with no age requirement. The original property has to have been substantially damaged or destroyed, which the BOE defines as more than half of the market or improvement value diminished. The disaster claim form is BOE-19-V.

What to file, and when. According to the BOE:

Situation	Form	Deadline
Age 55 or older	BOE-19-B	Within 3 years of the replacement’s purchase or completion
Severely and permanently disabled (any age)	BOE-19-D plus BOE-19-DC (physician certificate)	Within 3 years of the replacement’s purchase or completion
Wildfire or natural disaster victim	BOE-19-V	Within 3 years of the replacement’s purchase or completion

You file with the County Assessor where the replacement property is located, and at the time of filing you must own and live in the replacement as your principal residence. The BOE adds that if you miss the three-year window you may still qualify, but the benefit begins the year the claim is filed.

For a home in Los Angeles County, that office is the LA County Assessor, which lists a help desk on its home page. The BOE publishes a directory of every county’s Assessor and tax office if your replacement home is outside LA County.

Passing a home to your children: the family transfer rules

Many of the families I meet in the foothills are thinking about a home that has been in the family for decades. Prop 19 changed how this works, so it deserves its own section.

The BOE’s fact sheet says the parent-child exclusion, which is an exclusion from change in ownership, lets the transferee keep the taxable value of the transferor. The main conditions are:

• It applies to a family home (or a family farm). The BOE page says other real property no longer qualifies.
• The home has to continue as the family home of the transferee. The transferee must live in it as their primary residence within one year of the transfer.
• The transferee must file for the homeowners’ exemption or the disabled veterans’ exemption within one year of the transfer. If the claim is filed later, the exclusion begins in the year the claim is filed.
• If the property is transferred because of a death, the date of death is treated as the date of transfer.

The value cap. The exclusion has a limit. The value limit equals the property’s taxable value at the time of transfer plus $1 million, adjusted every other year by an inflation factor. The BOE lists these amounts:

Transfer date	Adjusted amount
Feb. 16, 2021 through Feb. 15, 2023	$1,000,000
Feb. 16, 2023 through Feb. 15, 2025	$1,022,600
Feb. 16, 2025 through Feb. 15, 2027	$1,044,586

If the market value is above the limit, the difference is added to the taxable value. The BOE’s example, using the original $1 million: a home with a taxable value of $300,000 and a market value of $1,500,000 has an excluded amount of $1,300,000. The $200,000 excess is added, so the new taxable value is $500,000. In the BOE’s words, if that home’s market value had been $1,300,000 or less, the child would not have to pay additional property taxes.

Grandparents and grandchildren. The BOE says the same conditions apply, except the grandchild’s parents (who would qualify as children of the grandparents) must be deceased.

How to claim. Form BOE-19-P (parent-child) or BOE-19-G (grandparent-grandchild), filed with the County Assessor where the property is located, within three years of the transfer date but before the property is transferred to a third party. The BOE fact sheet adds that a claim is also timely if filed within six months after the Assessor mails a supplemental or escape assessment notice for the transfer.

A very common misunderstanding is that the old “inherit and keep the tax value” rule still works the same way for any property a parent owns. The BOE’s description is narrower now: it centers on a primary residence that becomes the child’s primary residence, and it carries the value limit above. If you are weighing an inherited home that nobody in the family plans to live in, that difference matters. For anything involving a trust, an estate, or a probate, please talk to an attorney before listing or transferring the property.

Your LA County property tax bill: dates and basics

If you are selling or buying, you will see the bill terms below. The LA County Treasurer and Tax Collector publishes them.

The tax year. A fiscal tax year runs July 1 through June 30. The Tax Collector prepares and mails the Annual Secured Property Tax Bills in October, and the office says all bills are mailed by November 1.

Two installments. According to the Treasurer and Tax Collector:

Installment	Due	Delinquent after
First	November 1	Close of business on December 10
Second	February 1	Close of business on April 10

If a delinquency date falls on a Saturday or Sunday, it moves to the close of business on the next business day. Payments have to be received, or postmarked by the U.S. Postal Service, by the delinquency date. Late payment brings a 10 percent penalty on each installment, plus a $10 cost on the second installment.

Looking up and paying. You can look up a current-year amount using your Assessor’s Identification Number (AIN) at the county’s tax lookup page, which the Tax Collector says is available October 1 through June 30. If you did not receive a bill, you can request a duplicate. The page is clear that a missing bill does not relieve you of the responsibility to pay on time.

Impound accounts. The Tax Collector describes an impound or escrow account as one a taxpayer sets up with a lender to pay property taxes. Your closing statement also lists property tax escrow deposits. The county page does not explain how lenders process those payments, so ask your lender how yours works.

Supplemental bills after a purchase or new construction

This one surprises new owners. State law requires reassessment as of the first day of the month following an ownership change or new construction. The Tax Collector says a supplemental bill is an additional bill issued after that reassessment.

• An ownership change or new construction between January 1 and May 31 results in two supplemental assessments, and two supplemental bills. The first covers the rest of the fiscal year in which the event happened, and the second covers the following fiscal year.
• The county says lenders and financial institutions do not usually pay the supplemental bill, and urges owners not to ignore it. If your lender pays your annual bill from an impound account, the county says to contact the lender as soon as possible.
• A lower reassessment produces a refund rather than a bill.
• The Assessor offers a Supplemental Tax Estimator for estimating the amount.
• If you appeal an assessment, the county says you may appeal to the Assessment Appeals Board within 60 days of the mailing date on the notice or bill, but filing an appeal does not suspend your obligation to pay by the delinquency dates.

The county pages do not list due or delinquency dates for supplemental bills, so use the dates printed on the bill itself.

Common misunderstandings

“Prop 13 means my taxes can never go up much.” The assessment growth is capped at two percent a year, but that is the assessed value, not the whole bill. The BOE notes that the tax rate is one percent plus the rate needed for local voter-approved bonds, and the county bill can also include special assessments or direct levies.

“If I sell, I lose my low taxable value.” For most buyers, that is how the system works: the buyer’s purchase sets a new base year value. Prop 19 gives qualifying owners a way to carry their value to a replacement home, but only if they meet the conditions and file the claim.

“I can transfer my tax value to a home in another county.” Since Prop 19, the BOE says the replacement home can be anywhere in California. The claim is filed with the Assessor in the county where the replacement property is located.

“Any family home I inherit keeps my parents’ tax value.” The BOE’s current description requires that the home becomes the transferee’s primary residence, and the exclusion has a value cap.

Questions to bring to a CPA or attorney

These are the questions I would write on a card before an appointment:

1. Does my situation meet the age 55, severely and permanently disabled, or disaster requirements on the date my current home sells, and how do I document that?
2. How do the 105 and 110 percent timing rules apply if I buy my replacement after I sell?
3. Which of my two homes, if any, qualifies for the homeowners’ exemption right now?
4. If my replacement home is in another county, which Assessor do I file with, and what do they require?
5. If a parent’s home is going to a child, does the child plan to live there as a primary residence? What does the value cap mean for our numbers?
6. Is the home held in a trust or going through probate, and does that change the filing?

Where I come in

I do not give tax advice, and I will not guess at your numbers. What I can do is make sure your sale and purchase timing lines up with the questions your CPA is asking, point you to the right county office, and walk you through the real estate side of a move in the Glendale, La Canada Flintridge, and Altadena areas and the rest of the foothills. My family has been rooted in these hills for about 50 years, and I would rather you understand your options calmly than feel rushed.

If you would like to talk it through, call or text me at (818) 456-1696, or send a message through the contact page. No pressure, no pitch.

Frequently asked questions

What does Proposition 19 do in one sentence?

It lets qualifying homeowners (age 55 or older, severely and permanently disabled, or victims of a wildfire or natural disaster) transfer their taxable value to a replacement primary residence anywhere in California up to three times, and it narrowed the parent-child and grandparent-grandchild exclusions, according to the BOE.

How long do I have to buy the replacement home?

The BOE’s fact sheet says the replacement residence must be purchased or newly constructed within two years of the sale of the original property.

When are LA County property taxes due?

First installment due November 1 and delinquent after close of business on December 10. Second installment due February 1 and delinquent after close of business on April 10, according to the LA County Treasurer and Tax Collector.

This is general information, not legal, tax, or insurance advice. Talk to a California attorney, CPA, or licensed insurance agent about your situation. Rules, forms, and dollar amounts on this page were read from the sources listed below on October 23, 2026, and they can change.

Aubree Chavarriga, REALTOR(R), Trevino Properties, CalDRE 02232602.