Don't Overpay Property Taxes When You Downsize

If you've owned your home for a couple of decades, you already know the biggest hidden cost of moving isn't the moving truck — it's your property tax bill. I hear this from clients all the time: "Margie, I'd love to downsize into Trilogy, but I've been in my house for 30 years and I'm terrified of what my new tax bill will look like." Good news — for most of you, that fear is out of date. It's called Proposition 19, and it's one of the best tools I have when I'm helping someone make the move to a 55+ community here in Brentwood.

I'm not a tax advisor, and you should always run your specific numbers by a CPA or the county assessor before you make a decision. But as someone who's walked dozens of clients through this exact move, here's what you need to know.

What Prop 19 actually does

Before Prop 19 passed, if you sold your longtime home and bought a new one, your property taxes got reassessed to the new purchase price — which, given how much values have climbed since most of my clients bought their original homes, could mean your tax bill tripling or worse.

Prop 19 changed that. If you're 55 or older (only one spouse needs to qualify if you're married), you can now transfer the taxable value of your old home to a new one, anywhere in California, regardless of the new home's price.

That's a real shift from the old rules, which only let you do this within certain counties and only if the new home cost the same or less than the one you sold. Now you can buy up, buy in a different county, and still carry your old tax base with you.

The numbers that matter

A few specifics worth knowing:

• You can use this benefit up to three times in your lifetime.
• Buying equal or lower? Your taxable value transfers over dollar for dollar.
• Buying higher? You'll pay tax on your old base value plus the difference between the two sale prices — not the full new purchase price.

Timing changes the math, too:

• Buy before you sell — 100% of your old base value transfers
• Buy within one year of selling — 105%
• Buy in year two after selling — 110%

And two deadlines worth writing down:

• The replacement home must be purchased within two years — before or after — of selling the original.
• You must file your claim with the county assessor within three years of the purchase to get full retroactive credit.

Why this matters especially if you're eyeing Trilogy

For a lot of my clients moving into Trilogy at the Vineyards or one of Brentwood's other 55+ communities, this is the piece that makes the math work.

Here in Contra Costa County, the assessor's office handles the claim through a form called BOE-19-P — Claim for Transfer of Base Year Value to Replacement Primary Residence for Persons at least Age 55 Years. You can find it directly on the Contra Costa County Assessor's site, and I'm always happy to walk clients through it or point them to the right person in that office.

With Brentwood's median home value sitting right around $805,000 to $815,000 this summer, and 30-year mortgage rates hovering in the mid-6% range, a lot of longtime homeowners are realizing they can sell their larger family home, buy into a community like Trilogy with resort-style amenities and none of the yard work, and keep roughly the same property tax bill they've had for years.

That combination — a smaller mortgage payment (or none at all, if you're selling with substantial equity) plus a frozen tax base — is often the difference between "someday" and "let's actually look this spring."

What I'd tell you if we were sitting at my kitchen table

Every situation is different. Your original purchase date, your home's current value, whether you're moving within Contra Costa or leaving the county entirely — all of it changes your numbers.

What I always recommend is pulling your current assessed value from your property tax bill, getting a realistic sense of what your existing home would sell for in today's market, and then having a real conversation about what a replacement home actually costs before you assume the tax hit will be worse than it is.

I've lived in Trilogy for years now, and I've sat across the table from more neighbors than I can count who assumed Prop 19 wouldn't apply to them, or didn't know it existed at all. If you're on the fence about whether a move like this makes financial sense, I'd love to run the numbers with you — no pressure, just information so you can make the call that's right for you.

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