The Prop 19 base year value transfer is the reason a lot of my Newport Beach clients feel comfortable downsizing at all. It is also the part of the move that nobody does for you. Escrow closes, the keys change hands, and the lower tax base stays behind until someone files a two-page form with the county. That form is BOE-19-B, and it is less intimidating than it looks once you know what each section is asking.
The short answer: BOE-19-B is the claim a homeowner who was at least 55 when they sold files to move their taxable value to a replacement home. You file it with the assessor in the county where the new home is located, after you own and live in it, and within three years of buying it or finishing construction. In Orange County it goes to the Orange County Assessor, and the form asks for details on the new home, the old home, and you.
In this guide: What to gather first · Section A: the replacement home · Section B: the home you sold · Section C: you, the claimant · How the value test works · When and where to file · Questions I get
What should you gather before filling out BOE-19-B?
Most of the time spent on this form is spent looking for numbers. Pull these together first:
- Both closing statements. You need the purchase price and date for the new home and the sale price and date for the old one.
- The assessor's parcel numbers. Both are printed on the property tax bills.
- The recorder's document number for the new home's deed, if you have it. Your escrow or title officer can provide it.
- Identification showing your date of birth. The claim asks you to show you were at least 55 on the date the old home sold.
- The old home's latest tax bill and any supplemental bills, if it was in a different county from the new one. The form requires copies in that case.
- Proof the old home was your principal residence, if you did not have the homeowners' exemption on it. The Board of Equalization lists voter registration, vehicle registration, bank accounts, or income tax records as examples.
How do you complete Section A, the replacement home?
Section A is about the home you bought or built. It asks for the parcel number, the recorder's document number, the date of purchase, the purchase price, and the address. If you built rather than bought, there are separate lines for the date construction was completed and its cost.
Three yes or no questions follow. Do you live in the home as your principal residence? Is it a multi-unit property, and if so, which unit is yours? And is this new construction on a home that already received the transfer within the past two years? Most downsizers answer yes, no, and no.
How do you complete Section B, the home you sold?
Section B covers the original home: its parcel number, sale price, sale date, and address, which has to be in California. It asks whether it was your principal residence and, if you had moved out before the sale, the date it stopped being your principal residence. It also asks whether the home transferred to a parent, child, grandparent, or grandchild, and whether there was any new construction on it after the last tax bill and before the sale.
That family transfer question matters. Selling the house to a child and claiming your own base year value transfer are two different transactions with different rules, and I cover the family side separately in my guide to inheriting a home under Prop 19.
What does Section C ask about the claimant?
Section C is you: name, date of birth, and Social Security number, which the form describes as mandatory because the state uses it to enforce the three-transfer limit. It asks you to confirm you were at least 55 at the time of the sale, and whether you have received a base year value transfer for age or disability before. If you have, list the counties and parcel numbers. An eligible homeowner can use the transfer up to three times.
You then sign a certification under penalty of perjury that you live in the replacement home, that you were at least 55 when the original sold, and that everything on the form is accurate. The completed claim is confidential and not open to public inspection.
How does the Prop 19 value test work on this claim?
The form spells out the rule. The replacement home is treated as equal or lesser value if its full cash value, generally the purchase price, is no more than:
When the replacement is bought or built | Limit, as a share of the original home's value |
|---|---|
Before the original home sells | 100% |
Within the first year after the sale | 105% |
Within the second year after the sale | 110% |
If you stay under the limit, the old home's factored base year value becomes the new home's base year value. If you go over, the relief is partial: the amount above the limit is added to the value you carry over.
Here is a hypothetical to show the arithmetic. Suppose you sell a Newport Beach home for $2,400,000 and buy a replacement eight months later. The first-year limit is 105%, or $2,520,000. Buy at $2,450,000 and your old base transfers as is. Buy at $2,700,000 and the $180,000 above the limit is added to the carried-over base. You can run your own numbers with my Prop 19 calculator, and my guide to Prop 19 downsizing in Newport Beach walks through the rest of the rules.
When and where do you file BOE-19-B in Orange County?
File after you own the replacement home and live in it, because the claim requires that at the time of filing. For a home in Orange County, the form directs claims to the Orange County Assessor at 500 S. Main Street, First Floor, Suite 103, Orange, CA 92868-4512, or by mail to P.O. Box 22000, Santa Ana, CA 92702-2000. If your new home is in another county, that county's assessor is the one you file with.
The deadline for full relief is three years from the purchase or completion of construction. Filed later, relief starts with the calendar year you file, with no refund for the years before. And one timing detail catches buy-first owners: the transfer takes effect as of the latest qualifying event. If you buy before you sell, you pay the higher taxes on the new home until the old one closes.
File the homeowners' exemption on the new home as well. It is a separate form, and it also supports that the home is your principal residence.
Questions I get about filing BOE-19-B
Where do I file BOE-19-B if my replacement home is in Newport Beach?
With the Orange County Assessor, because the claim goes to the county where the replacement home is located. The form lists the office at 500 S. Main Street in Orange and a mailing address at P.O. Box 22000 in Santa Ana.
How long do I have to file the Prop 19 claim for a replacement home?
Three years from the date you bought the replacement home or completed its construction. A later claim can still be granted, but relief only starts with the calendar year you file.
Can I file BOE-19-B before I move into the new home?
No. You have to own and occupy the replacement home as your principal residence when you file.
What documents do I need for BOE-19-B?
Both closing statements, both parcel numbers, identification showing your date of birth, and, if the old home was in another county, its latest tax bill and any supplemental bills.
What happens if my replacement home costs more than my old home sold for?
If it is over the 100%, 105%, or 110% limit that applies to your timing, you still get partial relief. The amount above the limit is added to the base year value you carry over.
A note from Jade
I put this filing on every downsizing client's closing calendar, because it is the one step with a real dollar cost if it slips. If you are planning a move, my free Downsizing Blueprint maps the sale, the purchase, and the filings on one timeline.
Sources and further reading: Orange County Assessor, form BOE-19-B and instructions · Revenue and Taxation Code section 69.6 · BOE Letter to Assessors No. 2024/044 · Orange County Assessor, replacement homes for seniors · BOE Proposition 19. Figures and rules verified September 2026.
This is general real estate education, not legal or tax advice. Eligibility, value limits, and filing deadlines depend on your dates, title, and residency. Confirm your claim with your CPA, attorney, or the county assessor before filing.
