Prop 13 explained: what it caps, and what it does not

By los-angeles.com EditorialEdited by Dolev NehoraiLast updated October 16, 2026Figures checked against the State Board of EqualizationReviewed by Ryan Kimmel, CPA, CPA, California Board of Accountancy

Proposition 13 does two things. It caps the general property tax rate at 1% of assessed value, and it stops an assessed value rising by more than 2% a year while the property does not change hands. That second half is the one that matters in practice: it is why a long-standing owner in Los Angeles can pay a fraction of what the buyer next door pays for the same house.

What it does not do is cap your bill. Voter-approved debt service sits on top of the 1%, and direct assessments are flat charges that Proposition 13 does not reach at all. And the cap resets completely when the property is sold: the new owner starts from what they paid. The LA County property tax estimator works a bill out from that purchase price.

On this page

The two limits, and which one you feel
A purchase resets it, and that is the whole of the cliff
What Proposition 13 does not cap
Where it is written
Common questions

The two limits, and which one you feel

The rate limit is simple: 1% of assessed value for the general levy, written into the California Constitution in 1978. Nearly everybody's bill is higher than that, legitimately, because the same article lets a rate be levied to pay debt the voters approved.

The value limit is the one with the long tail. Once a base year value is set, it can be adjusted upward by no more than 2% a year, following the California consumer price index. Over twenty years of a rising market, that is the difference between a taxable value of a few hundred thousand and a market value of well over a million.

A purchase resets it, and that is the whole of the cliff

When a property changes hands, the county sets a new base year value at the price paid, and the clock starts again. The protection a seller spent thirty years accumulating does not transfer. This is why a buyer should never estimate their tax from the seller's bill, and why the first-year supplemental bill exists at all: it is the county charging the difference between the two values for the part of the year after the sale.

New construction is treated the same way, but only for what was built. Adding a unit or a room does not reset the base year value of the rest of the house: the new part is assessed at its own value and added. When a property is reassessed lists what counts and what does not.

LA County Property Tax Estimator

Estimates the annual property tax on an LA County property, including the homeowner's exemption and the supplemental bill a purchase triggers in the first year.

What Proposition 13 does not cap

Direct assessments are flat dollar charges rather than a percentage of value: Mello-Roos in districts that have one, and the smaller line items for lighting, sewer, flood control and the rest. They are listed separately on the bill and they are not in this estimate, so a real bill is this figure plus whatever those come to on your parcel. They are printed on the secured bill itself.

It also does not stop a value falling. In a market decline the taxable value is the lower of the factored base year value and current market value, which is a separate proposition and a review you have to ask the Assessor for.

Where it is written

Article XIII A of the California Constitution, added by Proposition 13 in June 1978, with the mechanics in the Revenue and Taxation Code. The State Board of Equalization publishes the plain-language overview, and the county Assessor applies it parcel by parcel. Every figure on this page is recorded with the source it came from and was checked by a CPA on October 16, 2026.

Common questions

Is Prop 13 still in effect?

Yes. It has been amended by later propositions, most recently in 2021 on how a base year value passes between family members and how an older owner can carry one to a new home, but the 1% rate limit and the capped annual increase are unchanged.

Does Prop 13 cap my whole property tax bill at 1%?

No. It caps the general levy at 1% of assessed value. Voter-approved bond debt is levied on top of that, which is why most bills in Los Angeles County come to more, and flat direct assessments are charged separately again.

Does my assessed value always go up by 2%?

By no more than 2%. The adjustment follows the California consumer price index, so in years when that came in below 2% the increase was smaller. It is a ceiling rather than a schedule.

If I remodel my kitchen, do I lose my Prop 13 value?

Ordinary maintenance and replacement does not reassess anything. New construction does, but only the part that is new: the county adds the value of what was built to your existing base year value rather than revaluing the whole property.

Related guides

The homeowner's exemption in Los Angeles CountyThe $7,000 homeowner's exemption takes about $87.50 a year off the tax on a home you live in. Who qualifies, how to claim it, and how to tell whether you have it.
Your first-year supplemental property tax billAfter a purchase the county bills the difference between the old assessed value and yours, prorated from the month you bought. Buy between January and May and it comes twice.
When is a property reassessed in California?A change of ownership and completed new construction reset an assessed value. A refinance, a transfer between spouses and ordinary repairs generally do not. Each has conditions.

The figures on this page were last checked by a person on October 16, 2026