How Does Prop 19 Work If You're Over 55 and Downsizing in California?

Last updated October 21, 2026

If you are at least 55, Prop 19 lets you sell your primary residence and carry its lower property tax base to a replacement home anywhere in California, up to three times. You must buy the replacement within two years before or after the sale, and if the new home costs more than the allowed limit, the difference is added to your tax base. You then file form BOE-19-B with the assessor in the replacement home's county within three years.

What does Prop 19 let a 55+ homeowner do?

California voters approved Proposition 19 on November 3, 2020, and its base-year value transfer rules took effect April 1, 2021. According to the State Board of Equalization (BOE), compared to the old Props 60 and 90, Prop 19 made three big changes for people age 55 or older:

• Location: the replacement home can be anywhere in California, not just the same county or one of a handful of participating counties.
• Value: the replacement can be of any value, with an adjustment if it costs more than the original.
• Frequency: you can use it three times, instead of once.

Both homes must be your principal residence. The BOE explains that the original home must be eligible for the homeowners' exemption at the time of sale or within two years of buying the replacement, and there is no minimum time you must have lived there.

How long do you have to buy the replacement home?

You have a two-year window on either side of the sale. Per the BOE FAQ, you can buy the replacement first and sell later, as long as the original home sells within two years of the purchase. The catch: if you buy first, you pay property tax on the replacement's full market value until the original sells, and there is no refund for that period.

What is the 100%, 105%, 110% value test?

The BOE defines "equal or lesser value" based on timing:

• 100% of the original home's value if you buy the replacement before selling.
• 105% if you buy within the first year after the sale.
• 110% if you buy within the second year after the sale.

If the replacement is at or under that limit, your factored base-year value transfers with no adjustment. If it is above, the excess is added on.

The BOE's own example: an original home sells with a full cash value of $400,000 and a factored base-year value of $100,000. A replacement bought in the first year after the sale costs $600,000. The limit is $400,000 x 105% = $420,000. The excess, $600,000 minus $420,000, is $180,000, which is added to $100,000 for a new taxable value of $280,000 (source).

Hypothetical for illustration only: say a Palos Verdes couple sells a home for $2,000,000 with a factored base-year value of $500,000 and, within the first year, buys a $1,500,000 single-story home. Because $1,500,000 is below 105% of $2,000,000 ($2,100,000), the $500,000 base would carry over with no adjustment. These are made-up numbers, not a quote; your assessor makes the actual determination.

How and when do you file?

The BOE filing checklist lists form BOE-19-B, Claim for Transfer of Base Year Value to Replacement Primary Residence for Persons at Least Age 55 Years, due within three years of the date the replacement is purchased or new construction is completed (BOE filing checklist). The claim is filed with the assessor of the county where the replacement home is located, after both transactions are complete and you are living in the new home. It is not handled through escrow. For a Los Angeles County replacement home, that means the Los Angeles County Assessor.

What changed for parent-child transfers?

Prop 19 also narrowed the parent-child exclusion for transfers on or after February 16, 2021. Per the BOE comparison chart, the exclusion now applies only to a family home that was the parent's principal residence and becomes the child's principal residence (or a family farm), and the exclusion for other real property such as rentals was eliminated. The child must file for the homeowners' exemption within one year, and the BOE-19-P claim within three years.

There is also a value cap: the factored base-year value plus an adjusted $1 million amount. For transfers from February 16, 2025 through February 15, 2027, the BOE lists that amount as $1,044,586. Market value above the cap is added to the child's tax base. This is a big reason many 55+ owners now weigh selling and using their own base-year transfer against holding the home for heirs.

Frequently asked questions

Disclaimer: This article is general information, not tax or legal advice. The BOE itself notes its summaries are not legal interpretation and encourages consulting an attorney. Before you sell or buy, please review your situation with a CPA or real estate attorney and confirm eligibility with your county assessor.