What a decline-in-value review is
California's Proposition 13 sets a base value for your home when you buy it, and lets it grow no more than 2% a year. That grown-up number is your Prop 13 value, and it is what most Los Angeles County homeowners are taxed on.
Proposition 8 adds one exception. If your home's market value on January 1 is below its Prop 13 value, the Assessor can tax you on the lower number instead. The County calls this a decline in value, and the request you file is the Decline-in-Value Review, Form RP-87.
Three things the Assessor says about it, in its own words:
- It's temporary. “Decline-in-value reassessments are not permanent, but last at least one year.”
- It's reviewed every year. Your value “may decrease or increase depending on the market value of your property on January 1 of each subsequent year.”
- It never goes above your Prop 13 value. “Your assessed value will never increase more than the trended base value.”
So a reduction lowers this year's bill. Next year the Assessor looks again. If the market recovers, your value can climb back toward the Prop 13 number faster than 2% a year, but never past it.
Who it helps
The test is one sentence from the Assessor: “You must demonstrate that on January 1, the market value of your property was less than its current assessed value.”
That is most likely to be true if:
You bought in 2022, 2023 or 2024
Your Prop 13 value started at your purchase price, near the top of the market. Homes like yours may have sold for less around January 1, 2026.
Nearby sales came in below your roll value
Two similar homes near yours sold for less than the County's number, close to January 1, 2026. That is the evidence the Assessor asks for.
You own a condo or a newer build
Compare with sales in your own building or tract, not the houses around it. The Assessor compares like with like.
Something hurts value the County can't see
Fire damage, a slide, major deferred repairs. (Homes damaged in the Eaton or Palisades fires may also qualify for the Assessor's separate Misfortune and Calamity relief.)
Who it usually doesn't help: anyone who has owned since the 2010s or earlier. Your Prop 13 value has grown 2% a year from an old purchase price, and today's market value is almost certainly above it. A review can't lower a value that is already below market.
Check your numbers
Two numbers decide whether you have a case.
1. The County's value
Look up your home on the Assessor's Property Search by address or by your Assessor's ID number (the AIN on your tax bill). The 2026 roll value, land plus improvements, is the number the review is measured against.
2. What similar homes sold for
The Assessor asks for “two comparable sales that sold as close to January 1, 2026 as possible, but no later than March 31, 2026.” A comparable sale, in the County's words, is “a property similar in location, zoning, size, number of bedrooms and bathrooms, age, quality and condition to yours that sold in the open market.”
The Assessor's website lists sales from the last two years, and the same information is available from any Assessor district office. Real estate sites and a local agent are other free sources.
If both sales come in meaningfully below the County's value, you have something to file. If they come in around it or above, you probably don't. And the Assessor says an application “submitted without comparable sales will still be accepted and processed,” so a thin case can still be filed.
Your opinion of value
The form has one box that matters most: “Your Opinion of Value as of January 1, 2026.” That is the number you are asking the Assessor to use.
It is your opinion, stated under your own signature. Make it the number your two sales support, not a wish. The Assessor's appraiser reads it beside the sales you list and any others on file.
If Jasmine Lane prepares your Package, the figure we give you is an opinion of value built from recorded sales of nearby homes. You decide whether to adopt it as your own before you type it in. We never enter it for you.
How that figure is built, and why it is the higher of two readings, is documented at jasminelane.app/methodology/california.
How to file — free, yourself
The County charges nothing to file. You don't need a representative, and no one can file it for you: the form carries your signature.
The County's dates, in its words. “This form MUST be filed between July 2 and November 30, 2026. Applications are valid if postmarked by November 30, 2026.” The Assessor adds that if November 30 falls on a weekend or legal holiday, an application filed or postmarked the next business day is on time.
Identify the home
Owner name, daytime phone, property address, mailing address, and your AIN. Online, the AIN and PIN unlock the form.
Describe it
Bedrooms, bathrooms, approximate square footage, and the number of units if it isn't a single home.
Enter your opinion of value
The number your sales support, as of January 1, 2026.
List two comparable sales
For each: address or AIN, sale date (no later than March 31, 2026), sale price, and a short description: size, year built, bedrooms and baths, how close it is to you.
Sign, submit, keep a copy
Online you get a confirmation number; save it. The Assessor asks you to keep a copy of the application “as a reminder to file an assessment appeal if you do not receive the Assessor's findings by October 1, 2026.” If no confirmation arrives within 48 hours of filing online, the Assessor says to mail the application instead.
After you file
An Assessor's appraiser reviews your form, the sales you listed, and other sales the office has. Then one of two things happens:
- The market value is below your Prop 13 value: the Assessor lowers your 2026 value to the market figure, and the 2026–27 bill reflects it.
- The market value is at or above it: in the County's words, “no change in assessed value will be made.”
You can check the status of your review on the Assessor's Decline-in-Value page (Status tab), and the details from your district office. The Assessor's line is 213-974-3211, toll-free 1-888-807-2111.
The review can't push you above your Prop 13 value.
If your home is taxed at its Prop 13 value, as most filers' are, the outcome is a lower number or, in the County's words, “no change in assessed value will be made.”
If your home already carries a decline-in-value reduction from an earlier year, the Assessor re-checks that value every year whether or not you file, and it can rise toward the Prop 13 value as the market recovers.
The Appeals Board is a separate process
The Decline-in-Value Review is an informal request to the Assessor. A formal appeal goes to the Assessment Appeals Board, a separate body that resolves differences of opinion about value between the Assessor and property owners.
The RP-87 states the dates this way:
- Keep a copy of your application “as a reminder to file an assessment appeal if you do not receive the Assessor's findings by October 1, 2026.”
- “If you disagree with the Assessor's decline-in-value conclusion, you may file an appeal with the Assessment Appeals Board. The appeal must be filed no later than November 30, 2026.”
- “You may appeal before the applicable deadline without waiting for a response to this claim.”
Applications come from the Appeals Board, not the Assessor: Assessment Appeals, Board of Supervisors or 213-974-1471. The RP-87 also notes you “may withdraw your AAB appeal without penalty, for any reason.”
Jasmine Lane does not prepare Appeals Board applications and does not appear before the Board. If you go that route, the County's own form and instructions are the guide.
While you're there — the Homeowners' Exemption
A different break, and a simpler one. If you own and live in your home on January 1, the Homeowners' Exemption takes $7,000 off its taxable value every year, about $70 to $85 a year in Los Angeles County. Once granted it stays on until you move.
Many homes don't have it. Your annual tax bill shows whether yours does, and the claim is a free one-page form from the Assessor. Our Homeowners' Exemption guide covers who qualifies, the dates, and how to claim it in Los Angeles County.
What Jasmine Lane prepares, and what it doesn't
Our Decline-in-Value Evidence Package is for owners who want the numbers done. In plain terms:
- We prepare, you file. The Package holds the comparable sales we relied on, an opinion of value, and the values to enter in each field of the RP-87, in the order the form asks. You sign in to the Assessor's site and file it yourself.
- We never contact the County. Nothing is signed, submitted, or discussed with the Assessor or the Appeals Board by us, before or after you file.
- $149, due only after your filing is confirmed. Nothing is charged, held, or invoiced before then, and nothing is owed if you decide not to file.
- Refunded if you don’t save more than $149. Savings are the Assessor’s reduction times your tax rate. In full, decided by June 30, 2027. This is a promise about our fee, not about what the Assessor will decide.
The full terms are the Service Agreement (California). Enter your address below and the site shows the County's value for your home and what nearby sales say, before anything else.