Proposition 19 in Calabasas & Westlake Village: How to Move Without Losing Your Property Tax Base

Can California homeowners 55+ transfer their property tax base when they sell?

Yes. Under Proposition 19, California homeowners who are 55 or older, severely disabled, or victims of a declared natural disaster can transfer the taxable assessed value of their primary residence to a replacement home anywhere in California — up to three times in their lifetime. In Calabasas, Westlake Village, and Agoura Hills, where many long-time homeowners carry Proposition 13 bases from the 1980s and 1990s, this benefit can mean saving $20,000 to $50,000 or more in property taxes annually on a replacement home. The benefit applies regardless of whether the replacement home costs more or less than what you sold, though a formula adjusts your new base if you're buying up.

If you've owned your home in Calabasas, Westlake Village, or Agoura Hills for 20 or 30 years, you already know what Proposition 13 has meant for you. Your annual property tax bill is based on what you paid for the house back then — maybe $350,000 or $450,000 — not what it's worth today. At $2.5 million or $3 million on the current market, the difference is enormous. We're talking $25,000 to $35,000 less in property taxes each year compared to what a new owner would pay on the same home.

That's an incredible advantage. And for a lot of homeowners in this market, it's become a golden handcuff.

The equity is there. The motivation to downsize, upsize, relocate, or simply change what your day-to-day life looks like is there. But the thought of losing that Prop 13 tax base — and suddenly paying $30,000 more per year on a replacement home — has kept a lot of people exactly where they are.

Proposition 19 changed that. Here's what it actually means for homeowners in the Conejo Valley and the West San Fernando Valley.

What Proposition 19 Does

California voters passed Proposition 19 in November 2020. The property tax transfer benefit went into effect in April 2021.

The core of Prop 19 is simple: if you're 55 or older, severely disabled, or a victim of a natural disaster or wildfire, you can transfer your factored base year value — your existing Proposition 13 tax base — from your current primary residence to a replacement home anywhere in California. You're not locked to the same county, the same city, or even the same price range. You can move to San Diego, Santa Barbara, Palm Springs, or the other side of Westlake Village. The portability is statewide. You can use this benefit up to three times in your lifetime.

Who Qualifies

You qualify for Prop 19's base year value transfer if at least one of the following applies:

- You're 55 or older at the time of the sale of your original property

- You're severely and permanently disabled

- Your home was substantially damaged or destroyed by a wildfire or other state or federally declared disaster

For the 55+ threshold, only one spouse needs to meet the age requirement. The property being sold must have been your principal residence. The replacement property must also become your principal residence within two years of the sale.

The Math That Changes Everything

Here's where it gets real for long-time homeowners in this market.

Say you bought your Calabasas home in 1992 for $400,000. Under Proposition 13, your assessed value has grown at no more than 2% per year since then — a slow compound that, after 34 years, puts your current assessed value somewhere around $785,000. At roughly a 1.2% effective tax rate for Los Angeles County, you're paying about $9,400 per year in property taxes. Your home is now worth $2.8 million.

If you sell and buy a $2 million replacement home without Prop 19, the new home gets reassessed at $2 million. At the same 1.2% rate, you're looking at $24,000 per year in property taxes — nearly $15,000 more annually than you're paying now, for the rest of the time you own the replacement home.

With Prop 19, you transfer your existing base year value to the new home. Your taxes on the replacement home start from your existing $785,000 base — not $2 million. The savings hold indefinitely.

If the replacement home costs less than what you sold: Your entire base transfers intact. You pay property taxes as if you'd bought the new home for $785,000.

If the replacement home costs more than what you sold: A formula adjusts your new base upward by the difference. If you sold for $2.8 million and buy a $3.2 million replacement, the $400,000 difference gets added to your old base: $785,000 + $400,000 = $1,185,000 new assessed value. Still dramatically lower than a full reassessment at $3.2 million — and a substantial savings every year going forward.

The Three-Use Lifetime Limit

Under prior California law (Propositions 60 and 90), homeowners could use the base year value transfer only once. Prop 19 expanded that to three times in your lifetime.

This matters for homeowners who anticipate more than one move — from a family home to a smaller home, then potentially to a different replacement later. It also matters for couples: each eligible homeowner has their own three-use allowance.

How to Apply

Prop 19 doesn't happen automatically. You have to file a claim with the county assessor of the county where your replacement property is located.

The filing timeline is important: you must file the claim within three years of purchasing the replacement property. You can also file before the sale of your original property, but only up to two years in advance.

If your replacement home is in Los Angeles County, the claim goes to the LA County Assessor's office using Form BOE-19-B. Each county has its own version of this form. Your escrow officer and real estate agent should have this on their checklist from the start of the transaction.

This is one of those steps that's easy to miss in the middle of a complex escrow — which is exactly why we walk our clients through it as part of the preparation process, not as an afterthought

What This Means for Sellers in This Market Right Now

We work with a lot of long-time homeowners in Calabasas, Westlake Village, Agoura Hills, and Woodland Hills who have significant equity and genuine reasons to move — but who've been sitting on the fence because of the property tax math.

Prop 19 doesn't eliminate every concern. If you're buying significantly above what you're selling for, your new base will be higher than your current one. But for homeowners who are downsizing, moving laterally, or relocating to another part of California, the math can shift dramatically in their favor.

We've watched this conversation change decisions. A couple in Agoura Hills who'd owned their home since the late 1980s, thinking about relocating closer to family, realized Prop 19 let them take their property tax base with them — to any county in California. A homeowner in Calabasas downsizing from a $3 million home to a $1.8 million property reduced both her square footage and her annual property tax bill substantially, because the replacement cost less and her base transferred intact.

If you're weighing whether it makes sense to sell, the property tax picture is one part of the equation. 

Frequently Asked Questions

Does Proposition 19 apply if I'm buying a more expensive home?

Yes, but with an adjustment. If you sell your primary residence and purchase a replacement that costs more, the difference is added to your current base year value. Your new assessed value will be your old base plus the price difference — not the full market value of the replacement home. This is still typically much lower than a full reassessment at the new purchase price.

Can I use Proposition 19 more than once?

Yes. Prop 19 allows eligible homeowners to use the base year value transfer up to three times in their lifetime. This is an expansion from prior law (Propositions 60 and 90), which allowed only one transfer per homeowner.

Does my replacement home have to be in Los Angeles County?

No. One of Prop 19's key improvements is statewide portability. You can transfer your base year value to a replacement home anywhere in California — any county, any city, any price range. The claim is filed with the assessor in the county where the replacement home is located.

How does the Los Angeles County Documentary Transfer Tax work when I sell?

The Documentary Transfer Tax in Los Angeles County is $1.10 per $1,000 of the sale price — roughly $2,750 on a $2.5 million sale. Unlike the City of Los Angeles, which imposes an additional transfer tax on sales over $5 million, unincorporated Calabasas and most incorporated areas in this market don't carry that additional layer. Your escrow officer will provide a full breakdown on your settlement statement before closing.

What happens if I wait too long to file my Prop 19 claim?
You have three years from the date you purchase the replacement property to file your claim with the county assessor. Miss that window and you lose the transfer benefit for that transaction. Your agent and escrow team should have this on their checklist from the start — don't leave it to the last minute.