Prop 19 Base Year Transfers for Homeowners 55+ in California
Under Proposition 19, a California homeowner who is 55 or older, severely and permanently disabled, or whose home was substantially damaged in a wildfire or Governor-proclaimed disaster can sell their primary residence and take its property tax base to a replacement primary residence anywhere in the state. The replacement must be bought or built within two years before or after the sale. Owners 55 and older and disabled owners can do this up to three times. If the new home is worth more than the old one, the difference is added to the transferred value; it doesn’t disqualify the move.
Prop 19’s base year value transfers have applied since April 1, 2021. They replaced the older Props 60, 90 and 110, which is why searches for “Prop 60” now lead here. Prop 19 also changed how parents pass homes to children, which we cover separately in Prop 19 and inherited homes. This page sticks to moving your own tax base, with the rules taken from the State Board of Equalization (BOE).
Who qualifies for a Prop 19 base year transfer
The BOE says only one of the three qualifications has to be met on the date the original home is sold.
- Age 55 or older: you must be 55 when the original home is sold, not when you buy the replacement. The BOE says a spouse under 55 doesn’t stop the other spouse from qualifying.
- Severely and permanently disabled: this applies at any age. You file a disability claim with a physician’s certificate.
- Wildfire or natural disaster victim: the disaster must be one the Governor proclaimed, and the home must have been substantially damaged, which the BOE describes as damage of more than 50% of the value of the land or the improvements. The damaged home must be sold.
Both homes have to be primary residences, and both have to be in California; the BOE confirms a home in another state doesn’t qualify. When you file, you must own and live in the replacement and be eligible for the homeowners’ or disabled veterans’ exemption. Under Property Tax Rule 462.520(g), only one co-owner can receive the benefit for a given transfer.
How the value test works
The transfer compares the full cash value (market value) of the two homes. Whether the replacement counts as “equal or lesser value” depends on when you buy it, measured against the original home’s value on the date of sale.
| When the replacement is bought or built | “Equal or lesser value” means up to |
|---|---|
| Before the original home is sold | 100% of the original home’s full cash value |
| Within the first year after the sale | 105% of the original home’s full cash value |
| Within the second year after the sale | 110% of the original home’s full cash value |
If the replacement falls within that limit, its taxable value equals the original home’s taxable value. If it’s above the limit, the amount over the limit is added to the transferred taxable value. Under the older Props 60 and 90, a more expensive replacement didn’t qualify at all.
A BOE example
In its December 2024 guidance to assessors, the BOE walks through a sale at $700,000 of a home with a factored base year value of $331,223. The replacement was bought within the first year for $750,000. The limit was 105% of $700,000, or $735,000, so the replacement was $15,000 over the limit, and its new taxable value was $331,223 plus $15,000, or $346,223.
Because the limit is tied to the original home’s market value, an accurate estimate of what your current home will sell for is the starting point for setting a replacement budget. A comparative market analysis or a home valuation gives you that number before you shop.
Timing: the two-year window works in either order
You can sell first or buy first, as long as the two transactions are within two years of each other. At least one of them has to have happened on or after April 1, 2021. The BOE treats the transfer date as the later of the sale or the replacement purchase (or completion of new construction).
- Buying first gives you the strictest test (100%) but lets you move straight from one home to the other. You’ll need to carry or bridge two homes; see buying before you sell.
- Selling first gives you more room (105% or 110%) and a known sale price, but you need somewhere to live in between. A seller rent-back can buy a few weeks.
- Contingent offers let you make the purchase depend on your sale; see home sale contingencies.
For a property with more than one unit, the BOE treats each unit as a separate residence, so only the unit you live in counts. There’s an exception: a home with an ADU or JADU can be treated as one residence if the BOE’s conditions are met, including that you live in one of the structures. A duplex with an ADU doesn’t qualify for that exception.
How Prop 19 differs from Props 60, 90 and 110
The older propositions applied through March 31, 2021. The comparison explains why many owners who ruled out a move under the old rules have options now.
| Feature | Props 60, 90 and 110 (through March 31, 2021) | Prop 19 (from April 1, 2021) |
|---|---|---|
| How many times | Once (a later disability transfer was the exception) | Up to three times for age or disability; disaster transfers don’t count toward the three |
| Where | Same county (Prop 60), or another county only if it had adopted an ordinance (Prop 90) | Anywhere in California; no county ordinance needed |
| Replacement value | Had to be equal or lesser value (100%, 105% or 110%) | Any value; the amount over the limit is added to the taxable value |
| Window | Two years before or after the sale | Two years before or after the sale |
Before Prop 19, the BOE listed only ten counties that accepted Prop 90 transfers from other counties as of November 2018: Alameda, Los Angeles, Orange, Riverside, San Bernardino, San Diego, San Mateo, Santa Clara, Tuolumne and Ventura. The Sonoma County Assessor states that Sonoma did not allow intercounty transfers, and neither Napa nor Marin was on the BOE’s list, so a move between those North Bay counties couldn’t carry a tax base under the old rules. The BOE also says a past Prop 60, 90 or 110 transfer doesn’t reduce the three transfers allowed under Prop 19.
Filing the claim
You file with the assessor of the county where the replacement home is, after both transactions have closed and you’ve moved in. The BOE publishes sample forms; the county assessor supplies the forms you actually file.
| Who | Form |
|---|---|
| Age 55 or older | BOE-19-B, Claim for Transfer of Base Year Value to Replacement Primary Residence for Persons at Least Age 55 Years |
| Severely and permanently disabled | BOE-19-D, plus BOE-19-DC, Certificate of Disability |
| Wildfire or natural disaster victim | BOE-19-V |
The deadline is three years from the purchase of the replacement or completion of its new construction. The BOE says a late claim gets prospective relief only, starting with the January 1 lien date of the year you file, so the tax savings for the years you missed are lost. In Sonoma County, the Assessor’s Office is at 585 Fiscal Drive, Room 104F, Santa Rosa, and its main office line is (707) 565-1888.
A purchase usually triggers a supplemental tax bill. Ask the assessor how supplemental assessments are handled while your claim is pending, so a bill based on the full purchase price doesn’t catch you off guard.
A downsizing timeline that keeps the transfer intact
- Check eligibility. Confirm you (or your spouse) will be 55 on the sale date and that both homes are, or will be, your primary residence.
- Price the current home. Get a realistic market value, because it sets the 100%, 105% or 110% limit.
- Set the replacement budget. Decide whether to stay under the limit or accept a higher taxable value, and estimate the property tax either way.
- Choose the order. Buy first, sell first or use a contingent purchase, based on cash, financing and where you’ll live in between.
- Close both within two years. Put both dates on the calendar the day you open the first escrow.
- Move in and file. File the BOE-19 claim with the replacement county’s assessor as soon as you live there, well inside the three-year deadline.
Prop 19 affects property tax only. The income tax on your sale is a separate question; see capital gains on a California home sale. For the wider planning picture, our guide to downsizing in the North Bay covers housing choices, and our Sonoma County 55+ communities page lists age-restricted options.
Questions people ask
Is Prop 60 still in effect in California?
No. Props 60, 90 and 110 applied through March 31, 2021. Base year value transfers by owners 55 and older, disabled owners and disaster victims now fall under Prop 19, which applies from April 1, 2021.
Can I use Prop 19 more than once?
Yes. Owners who qualify by age or disability can transfer a base year value up to three times. The BOE says disaster-based transfers don’t count toward that limit, and earlier Prop 60, 90 or 110 transfers don’t either.
Can I move to another county and keep my property tax base?
Yes, anywhere in California, with no county ordinance needed. A home outside California doesn’t qualify.
What happens if my new home costs more than my old one?
You still get the transfer. The amount above the limit (100%, 105% or 110% of the old home’s value, depending on timing) is added to the transferred taxable value.
Do both spouses have to be 55 for Prop 19?
No. The BOE says a spouse under 55 doesn’t keep the other spouse, who is 55 or older, from qualifying, as long as the other requirements are met.
Can I buy the new home before selling the old one?
Yes, if the sale closes within two years. Buying first means the replacement must be at or below 100% of the old home’s value to carry the tax base over unchanged.
What is the deadline to file a Prop 19 claim?
Three years from the purchase of the replacement home or the completion of its new construction. A late claim gets relief only from the January 1 lien date of the year you file.
Does Prop 19 apply to a second home or rental?
No. Both the original and the replacement must be your primary residence. For a multiunit property, only the unit you live in counts.
This is general information, not legal or tax advice; talk to the county assessor, a property tax attorney or a CPA about your situation.
If you’re planning a move and want both closings to line up with the Prop 19 window, we can help you price your current home, set a replacement budget and sequence the two escrows. Start with our home-selling process, see how we sell homes in Sonoma, or visit our seller services page.
Sources & notes
- California State Board of Equalization: Proposition 19
- California State Board of Equalization: Introduction to Prop 19 (April 2023)
- California State Board of Equalization: Letter to Assessors 2021/019, Prop 19 base year value transfer guidance (May 11, 2021)
- California State Board of Equalization: Letter to Assessors 2024/044, base year value transfer FAQs (December 11, 2024)
- California State Board of Equalization: Prop 19 base year value transfers study questions
- California State Board of Equalization: Property tax forms (BOE-19-B, BOE-19-D, BOE-19-DC, BOE-19-V)
- California State Board of Equalization: Transfer of base year value for persons age 55 and over, Props 60/90
- Sonoma County Assessor: Replacement dwelling exclusion
Last reviewed October 2026 by Matthew Martinez.
