If you are 55 or older and have owned your North County home for a while, your property‑tax bill is probably one of the best things about it. Proposition 19 means you do not have to give that up to move. You can carry your low tax base to a new primary residence anywhere in California — and this page shows exactly how much you would pay on the next home.
I am a real estate broker, not a tax advisor, so treat the numbers here as planning estimates and confirm the specifics with the County Assessor or your CPA. But this is one of the most valuable and least understood rules in California real estate, and for a lot of longtime owners it is the difference between staying put and finally making the move that fits your life now.
What would your tax bill be on the next home?
Enter your current home, the one you are eyeing, and when you would buy. Nothing here asks for your email.
Real North County examples
Downsizing to something less expensive
Say you bought decades ago and your home is now worth about $2,000,000, but thanks to Proposition 13 it is assessed at roughly $300,000 — so you pay around $3,450 a year. You sell it and buy a $1,500,000 single‑level home closer to the grandkids.
Because $1,500,000 is below your adjusted value, Prop 19 carries your entire $300,000 base straight to the new home. You keep paying about $3,450 a year instead of the roughly $17,250 a new buyer would owe on that same house — a saving of about $13,800 every year. Note the new home still costs far more than you originally paid decades ago; that does not matter. Prop 19 compares against your old home's current value, not your old purchase price.
Moving up to something more expensive
Same $2,000,000 home assessed at $300,000, but this time you buy a $2,500,000 home within a year of selling. You do not lose the benefit — you just add the difference at the top. Your 105% adjusted value is $2,100,000, the “excess” is $400,000, so your new assessed value is $300,000 + $400,000 = $700,000.
You pay about $8,050 a year instead of the roughly $28,750 a normal buyer would owe on a $2.5M home — still saving around $20,700 a year while buying up. Buy before you sell and the threshold is 100% instead of 105%, which nudges the number a little; the calculator above lets you test the timing.
How Prop 19 actually works
Who qualifies. You must be at least 55, or severely and permanently disabled, or replacing a home lost to a wildfire or declared disaster. Both the home you sell and the home you buy have to be your principal residence.
Anywhere, any value, up to three times. The old Prop 60/90 rules generally limited you to an equal‑or‑lesser home in the same or a reciprocal county, one time. Prop 19 lets you move anywhere in California, to a home of any price, and do it up to three times if you qualify by age or disability. That is what makes it genuinely useful.
Timing sets the threshold. You have two years from selling your original home to buy or build the replacement, before or after the sale. The comparison value is your old home's market value adjusted by 100% if you buy before selling, 105% within the first year after, or 110% within the second year. At or below that adjusted value, your whole base transfers; above it, only the excess is added on top.
What it does not do. Prop 19 transfers your Proposition 13 base — the roughly one percent ad‑valorem tax. It does not reduce Mello‑Roos or other special assessments on the new home, which are billed separately. If your next neighborhood carries Mello‑Roos, plan for it on top; our financing calculators treat that as a real input.
How you claim it. File Form BOE‑19‑B with the San Diego County Assessor within three years of buying the replacement home. The Assessor sets the official value; everything here is an estimate for planning.
Thinking about a move like this?
The order of operations — when you list, when you buy, how the timing threshold falls — can be worth thousands. That is exactly the kind of thing we help longtime owners map out, with no obligation.
Prop 19, answered
What is Proposition 19 and who does it help?
Proposition 19 took effect in 2021. Its base-year-value transfer lets a homeowner who is at least 55, severely and permanently disabled, or a victim of a wildfire or natural disaster move to a replacement primary residence and take their existing Proposition 13 assessed value with them, instead of being reassessed at the new home's full purchase price. In a high-priced market like North County that difference can be many thousands of dollars a year.
How is the new assessed value calculated if I buy a MORE expensive home?
You still keep your low base; you only add the difference at the top. The county compares your new purchase price to your old home's market value, adjusted by 100 percent if you buy before selling, 105 percent if you buy within one year of selling, or 110 percent within two years. If the new home costs more than that adjusted figure, the excess is added to your transferred base. Example: old home worth 2,000,000 dollars with a 300,000 dollar base, new home 2,500,000 dollars bought within a year. The 105 percent adjusted value is 2,100,000, the excess is 400,000, so your new assessed value is 300,000 plus 400,000, or 700,000 dollars, not the full 2,500,000.
What if I downsize to a LESS expensive home?
Then you carry your entire base over with no addition, as long as the new home's price is at or below your adjusted value. Example: you sell a 2,000,000 dollar home that is assessed at 300,000 and buy a 1,500,000 dollar home. Because 1,500,000 is below your adjusted value, your new home is assessed at 300,000 dollars. Note the new home is still more expensive than what you originally paid decades ago, but that does not matter for Prop 19 — the comparison is against your old home's current market value, not your old purchase price.
How many times can I do this, and how long do I have?
A person who qualifies by age or disability may transfer up to three times in their lifetime. You must buy or build the replacement primary residence within two years of selling the original, either before or after the sale. Both homes must be your principal residence.
Does Prop 19 lower Mello-Roos or special assessments too?
No. Prop 19 transfers your Proposition 13 base value, which drives the roughly one percent ad valorem property tax. Mello-Roos and other special assessments on the new home are separate line items and are charged in full regardless. If the new neighborhood carries Mello-Roos, budget for it on top of the transferred tax. Our financing page has a calculator that treats Mello-Roos as a real input.
How do I actually claim it?
You file Form BOE-19-B, the claim for transfer of base year value for persons at least age 55, with the San Diego County Assessor. It must be filed within three years of buying or completing the replacement home. The Assessor sets the official value; the estimate here is only for planning. This is a tax matter, so confirm the specifics with the Assessor or your tax advisor before you rely on any number.
Is this the same as the old Proposition 60/90?
It replaces them and is much broader. The old rules generally required an equal-or-lesser replacement, in the same or a reciprocal county, one time. Prop 19 lets you move anywhere in California, buy a home of any value, and do it up to three times — which is why it opens up moves that used to be off the table.
The Lund Team, Inc. · DRE #01394870 · 760.438.0800 | Tyson Lund · Broker · DRE #01385039 · tyson@lundteam.com
The Lund Team, Inc. is a licensed California real estate brokerage. We are not tax advisors or attorneys, and nothing on this page is tax, legal, or financial advice. Proposition 19 rules, thresholds, forms and property-tax rates are set by the State of California and the County and change over time; the assessed value on any home is determined solely by the County Assessor upon a filed claim. Calculator results are estimates for planning only. Verify everything with the San Diego County Assessor and your own tax advisor before acting. Information deemed reliable but not guaranteed. Equal Housing Opportunity.