Proposition 19 in California

Proposition 19 in California: How San Francisco Homeowners Can Cash Out and Keep Their Old Tax Bill

A $300K House From 1995, a $2M Sale in 2026 — and a Tax Bill You Can Take With You

There's a rule in San Francisco real estate that most homeowners never think about, even though it can be worth hundreds of thousands of dollars. A house bought in 1995 for $300,000 is selling this summer for roughly $2,000,000. But the entire time the owner has lived there, they've paid property tax based on that old, frozen assessed value — not the current market price. Under Proposition 19, that low tax base can be carried over to a new home: in Sonoma, Santa Barbara, Palm Springs, or almost anywhere else in California.

This breakdown is based on guidance from Big Data Realty, a brokerage licensed in California and Florida that runs the numbers before a client picks a town, a house, or an agent.

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Proposition 13: Why the Tax Bill Barely Moved for Decades

The underlying protection comes from Proposition 13, which caps the annual growth of a property's assessed (taxable) value at 2%, no matter how fast the market price rises. A house bought for $300,000 in 1995 is assessed today at only about $550,000 — even though it's worth several times that on the open market.

San Francisco taxes roughly 1.2% of assessed value, which means:

• the owner who bought in 1995 pays around $6,500 a year;
• a buyer who pays $2,000,000 for the identical house next door pays around $24,000 a year.

Same street, same fog — but a fourfold difference in tax bills. And every year the market outpaces that 2% cap, the gap widens further. That's a big reason so many long-term owners never sell, even at record prices: they're not stuck, they've simply done the math.

Proposition 19: The Key That Unlocks the Old Tax Base

Since April 2021, Proposition 19 has allowed eligible homeowners to carry that frozen tax base with them when they sell their primary residence and buy a new one. It doesn't apply to everyone — four conditions have to be met.

The Four Conditions for Proposition 19

1. Age or status. You must be 55 or older at the time of sale, or severely and permanently disabled, or a victim of a wildfire or a declared disaster.
2. Primary residence only. Both the old and new homes must be your main residence — not a rental and not a vacation property.
3. Timing. You must buy the new home within two years before or after selling the old one.
4. Filing deadline. You must file a claim with the assessor's office in the county where the new home is located, within three years.

Meet all four, and the new home can be located anywhere in California, at any price. If you buy for equal value or less, your entire taxable base transfers over. If you buy for more, only the difference between the two prices gets added to your existing base.

This is a major change from the old rules, which allowed the transfer only once, only within the same county, and only into a cheaper home. Under Proposition 19, you can use this benefit up to three times in your lifetime, and you can move anywhere in the state.

Why San Francisco's Market Makes Selling Now Especially Attractive

According to the California Association of Realtors' July count, San Francisco is in one of the tightest seller's markets in years:

• about one month of housing supply;
• median home price at $2,050,000, up 25% year-over-year;
• the average winning bid came in 26% over asking — the biggest premium in 21 years;
• in the first half of the year, 144 homes sold at least a million dollars over asking, compared to just 8 the year before.

Demand is being driven by an influx of workers tied to the AI hiring boom, against a backdrop of almost nothing available to buy.

Where to Move: Comparing California Counties

Selling in San Francisco can buy significantly more house — and more land — almost anywhere else in the state.

Sell one house in San Francisco, and in some counties you could buy two homes and still have money left over.

A Real Example: What the Numbers Look Like

Scenario one: Sell in San Francisco for $2,300,000. Buy in Sonoma for $1,200,000 within a year.

• Under Proposition 19, the taxable value stays at $550,000.
• The new tax bill is roughly $6,500 a year.
• A neighbor who buys the same house at market price pays about $14,000 a year.

Scenario two — buy cheaper. Take Sonoma's median instead, at $840,000. The tax base still transfers in full, and roughly $1,000,000 is left over. After selling costs and capital gains tax (your CPA can give you the exact number), that might net out to around $700,000 — enough for down payments on two rental homes near Sacramento's median of $540,000. That's two properties and two rent checks a month, funded by a house you already owned.

One important catch: Proposition 19 only covers the home you live in. Rental properties are taxed at full market value based on what you paid for them.

There's also a timing mismatch to plan around: you're selling into a one-month-supply market, but buying into a market with three months of supply or more — nearly seven in Napa.

How to Pick a Location Without Getting Sold on a Town

The approach used at Big Data Realty is to pick the destination before picking the agent:

1. Build a list of what actually matters — stairs, yard space, drive time to family, sale timing.
2. Compare several geographies against that list, with no financial stake in any particular town.
3. Let the data point to a location.
4. Only then match agents — a listing agent for the sale side and a buyer's agent for the purchase side, chosen based on actual closed-sale performance rather than personal pitch.

In one such case, a family that had owned a home in the Sunset District since 1994 ran six geographies against their criteria (stairs, garden, an hour's drive to grandchildren in Walnut Creek, sale timing) and landed on Lafayette — Healdsburg lost out on drive time.

The Counterintuitive Part: Where It's Actually Best to Buy

It's tempting to assume the cheapest county is the best deal. The data suggests otherwise: the county where San Francisco sale proceeds go furthest isn't Solano, the cheapest option — it's Napa. Napa has nearly seven months of supply, homes take about 85 days to sell on average, and deals are closing below asking price.

In other words, it often matters more to buy where the seller has the least leverage than to chase the lowest sticker price.

Frequently Asked Questions About Proposition 19

Who qualifies for the Proposition 19 tax base transfer? Homeowners 55 or older, those with a severe and permanent disability, and victims of wildfires or officially declared disasters — provided both homes are their primary residence.

How many times can the benefit be used? Up to three times in a lifetime, compared to just once under the old rules.

Can you move to any county in California? Yes. As long as all conditions are met, the new home can be in any California county, regardless of price.

What happens if the new home costs more than the one you sold? Only the difference between the sale price and the purchase price gets added to your carried-over taxable base.

Does the benefit apply to rental properties? No. Proposition 19 only applies to a home that serves as your primary residence.

The Bottom Line

Proposition 13 kept many San Francisco homeowners in place for decades — moving meant a sudden jump in property tax. Proposition 19 removes that barrier, letting eligible owners carry their low tax base to a new home anywhere in California, subject to age and timing requirements, and up to three times in a lifetime.

If a San Francisco home no longer fits your life, the smartest first step isn't picking a town or an agent — it's running the actual numbers: what you can net from a sale, where that tax base can go, and what it means long-term. Big Data Realty offers that first conversation, with the numbers, at no cost.

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