Prop 19 calculator

Can I keep my property tax base if I move between Los Angeles County and San Luis Obispo County?

Usually, yes. If at least one owner is 55 or older, Proposition 19 lets you carry your current taxable value to a replacement home anywhere in California, up to three times, as long as you buy within two years of selling. If the new home costs more, part of the difference is added.

Facts reviewed September 25, 2026Re-checked quarterly and when the rules change.

Step 1: A few quick questions

Will at least one owner be 55 or older when the current home sells?

Are both homes your primary residence?

Have you used this benefit fewer than three times?

Transfers under the older Props 60 and 90 don’t count.

Step 2: The home you’re selling

Total assessed value (land plus improvements) on your tax bill, before exemptions.

Step 3: The home you’re buying

When will you buy it?

Your numbers stay in this browser unless you ask us to email them.

Your estimate

Your estimate appears here once you’ve added the three questions, your expected sale price, your current taxable value, the new home’s price, where you’re buying, when you’ll buy.

Estimate only. The county assessor decides eligibility and value. This isn’t tax or legal advice.

How Prop 19 works

  1. Step 1

    Sell your home

    At least one owner is 55 or older on the day it sells, and it’s your primary residence.

  2. Step 2

    Buy within two years

    Before or after the sale, anywhere in California. It becomes your primary residence.

  3. Step 3

    File form BOE-19-B

    With the assessor of the county where the new home is, within three years of buying it.

Moving between the two counties

Los Angeles County to San Luis Obispo County

Prop 19 applies anywhere in California, so this move follows the same rules as any other. The claim goes to the county where the new home is. File form BOE-19-B with the San Luis Obispo County Assessor within three years of buying it.

Each county publishes its own property tax rates, and they vary by location within the county. After the move, your carried-over taxable value is taxed at the San Luis Obispo County rate for the new home. The rate you paid in Los Angeles County no longer applies.

San Luis Obispo County to Los Angeles County

The rules are the same in this direction. File form BOE-19-B with the Los Angeles County Assessor, where the new home is, within three years of buying it.

Your carried-over taxable value is then taxed at the Los Angeles County rate for the new home. Those rates also vary by location. The calculator above uses each county’s published table.

Common questions

What happens if the new home costs more? →How long do I have after I sell, and when do I file? →Prop 19 or capital gains: which matters more when selling a long-held home? →Should I buy before I sell? →

Sources

  1. California State Board of Equalization: Proposition 19 Fact Sheet (Publication 801)
  2. Los Angeles County Assessor: Proposition 19
  3. San Luis Obispo County Assessor: Base Year Value Transfers (Prop 19)
  4. Los Angeles County Auditor-Controller: FY 2026-27 property tax rates
  5. San Luis Obispo County Auditor-Controller: FY 2025-26 property tax rates
  6. California State Board of Equalization: Base Year Value Transfers for Persons 55 and Older (Publication 800-3)
  7. California State Board of Equalization: Proposition 19 questions and answers (Letter To Assessors 2021/019)
  8. California State Board of Equalization: Base year value transfer questions and answers (Letter To Assessors 2024/044)
  9. City of Los Angeles Office of Finance: Measure ULA