Factored base-year value
The taxable value the assessor carries, which is not always the same as market value or the last sale price.
Home · Free tools · Prop 19 tax transfer
Southern California · November 14, 2026
Calculators
Proposition 19 property-tax transfer calculator
California's Proposition 19 changed how some homeowners can take a taxable value with them when they buy a replacement home, and how some parent-to-child transfers of a family home are treated. This calculator is a planning estimate using the rules described by the official Board of Equalization page. It is not a determination by an assessor and not tax advice.
Estimate · confirm with the county assessor
Prop 19 property-tax calculator
Estimate only. Not tax, legal or assessor advice, and not a determination of eligibility. The county assessor decides the value after you file a claim. Supplemental bills, partial interests, new construction and Proposition 8 reviews are not modeled.
Prop 19 in plain English: keeping a low tax base when you move
Proposition 13 keeps a long-time owner’s taxable value far below market. Proposition 19, approved by voters in November 2020, decides when that low value can follow you. Since April 1, 2021, a homeowner who is 55 or older, severely and permanently disabled, or whose home was damaged by wildfire or natural disaster can sell a principal residence and carry its taxable value to a replacement anywhere in California, up to three times for the age and disability groups, under California property tax rules.
The value test. The replacement must be bought or newly built within two years of the sale, before or after. If it costs no more than the original home’s value, the old taxable value moves over as is. The allowance is 100% of the original’s value if you buy first, 105% if you buy within a year after selling, and 110% in the second year. Anything above that is added to the transferred value. That is the worked example in the calculator: $600,000 − $420,000 = $180,000, plus the $100,000 taxable value, equals $280,000.
Filing. The relief is not automatic and does not go through escrow. File a claim with the assessor in the county where the new home is, within three years of buying it. If you buy before you sell, the new home is taxed at full value until the original sells. Expect a supplemental bill either way.
Parents and children. Prop 19 also narrowed the old Prop 58 exclusion. For transfers on or after February 16, 2021, only a family home that stays a principal residence keeps the parent’s value, and only up to the parent’s taxable value plus an amount that started at $1 million and is adjusted every two years, now $1,044,586 for transfers from February 16, 2025, through February 15, 2027. The child must file for the homeowners’ exemption within a year and file the family-transfer claim within three years. Rentals and second homes are reassessed.
Before you list or buy: ask the county assessor to confirm eligibility and the transferable value, and talk with a tax adviser. This calculator shows the arithmetic; the assessor decides the result. It leaves out supplemental bills, partial interests, new construction, and similar limits.
Who this is for, and when to use it
Homeowners who are 55 or older, or who are severely disabled, or who are replacing a home after a disaster, use the transfer estimate when they are thinking about a move. Families who expect to inherit or receive a family home use the parent-to-child notes to understand that the exclusion is limited. Use this page before you list, buy or transfer, then file the official claim with the assessor if you think you qualify.
Key terms
Replacement home
The home you buy or newly construct as a replacement, which can be anywhere in California under current Prop 19 transfer rules, within value limits.
Value difference
If the replacement home costs more than the original, part of the difference can be added to the transferred value. The official formula is what the calculator follows.
Family home exclusion
A limited parent-to-child (or grandparent-to-grandchild, in some cases) exclusion for a family home that the heir occupies as a principal residence, with a value cap. This is narrower than the older rule many families remember.
Claim window
Transfers are not automatic. You must file the official form with the assessor within the time allowed.
How to use this, step by step
- Read the official Board of Equalization Proposition 19 page so you know which set of rules you are looking at (a move, a disaster, or a family-home transfer).
- Enter the current taxable value and the values the calculator asks for. Use assessor figures, not a guess at market value, when you have them.
- Read the estimate as a planning range, including any added value if the new home costs more than the old one.
- Confirm whether you meet the age, disability, disaster or family-home occupancy rules; the calculator cannot check those for you.
- If you will proceed, file the official claim with the assessors involved, on time, and keep copies.
Costs, timelines, and common pitfalls
The difference between a transferred base and a new Proposition 13 base at the purchase price can be thousands of dollars a year, so a missed claim is costly. Filing the form is generally free, but a late or incomplete claim can be denied. Common pitfalls include assuming the old parent-to-child rule still applies, buying a much more expensive home and underestimating the added value, or moving before you understand the timing of the sale and the replacement purchase. Deadlines are official and strict.
County-by-county notes
Orange County
The Assessor, Clerk-Recorder and Treasurer-Tax Collector are separate offices. Orange County does not publish official blank grant or quitclaim deeds. Confirm exemptions and payment addresses on the official tax collector and assessor sites.
Los Angeles County
The Assessor, Registrar-Recorder/County Clerk and Treasurer and Tax Collector each publish their own lookup tools and forms. Many property-tax claims are filed with the Assessor.
Riverside County
The Assessor-County Clerk-Recorder publishes many of the sample deeds and tax forms used countywide, including in Moreno Valley and Temecula.
San Bernardino County
The Assessor/Recorder and the Tax Collector publish property information and payment pages. Supplemental bills and exemption claims are easy to mix up; read the official letter.
San Diego County
The Assessor/Recorder/County Clerk publishes courtesy deed forms and property-tax claims. Confirm the current packet on the official site before you record or file.
Before you start
- Have the latest assessed or factored base-year value for the current home, from the assessor, not only a market estimate.
- Have a target price or assessed outlook for the replacement home.
- Confirm you meet the age, disability, disaster or family-home occupancy conditions that apply to your path.
- Note the official filing deadline and which county assessor receives the claim.
- Talk with the assessor or a qualified tax professional if two counties, a trust, or a partial interest is involved.
A short real-estate example
Questions
Can I transfer my tax base to another California county?
Under current Proposition 19 transfer rules, a qualifying replacement home can be anywhere in the state, within the value limits. Confirm with both assessors.
Does this apply automatically at closing?
No. You must file the official claim and meet the rules, including timing.
What happened to the old parent-to-child rule?
It is narrower than many families remember. The current exclusion is focused on a family home the heir occupies, with a value cap. Read the official BOE page.
I am not yet 55. Can I use the transfer?
The move-related transfer is for homeowners who are 55 or older, or who meet the disability or disaster rules. Age is not a guess the calculator can make for you.
Is the calculator an assessor determination?
No. Only the assessor can set the official value after you file.
Where is the official claim form?
On the Board of Equalization page and on the assessor's site for the county. We also keep tax forms on our property-tax forms page.
Does a trust or an LLC change the result?
It can. How title is held matters. Get advice before you transfer an entity-owned home.
Official resource links
We link only official government or court pages. Confirm the current version on the official site.
Questions about a specific home or transaction? Call or text 833-THIS-BROKER (833-842-7465), text us, or request a call. Dr. Hamid Rowshan, Choice of America. DRE #02004794, company DRE #02240008.
This page is general information for Southern California homeowners, buyers, sellers and renters. It is not legal, tax, insurance or lending advice, not a loan offer, and not a substitute for the official agency, court, lender or insurer that will handle your file. Rules, fees, maps and forms change. Confirm every figure and every filing with the official office before you act.