Is Your LA Home Over-Assessed? How to Appeal Your Property Tax Before the November 30 Deadline

How Does the LA County Property Tax Appeal Process Work?

Los Angeles County homeowners whose current market value is lower than their Prop 13 assessed value can file a Decline-in-Value appeal under Proposition 8 to temporarily reduce their property tax bill. There are two paths: the free RP-87 informal review with the Assessor, or the $46 AAB-100 formal appeal before the Assessment Appeals Board. LA County recommends filing both on the same day. The deadline for 2026 is November 30, and missing it means waiting another full year.

By Paul Blair | September 18, 2026

If you bought in Los Angeles County in 2024 or 2025, there is a real chance you are paying property taxes on a value your home no longer supports.

The insurance crisis that followed the early 2025 wildfires hit hillside and coastal neighborhoods especially hard. Pacific Palisades, Altadena, Malibu, the Hollywood Hills. Values softened. Insurance premiums jumped, or coverage simply disappeared. Buyers who closed at peak prices in those years may now find their Prop 13 assessed value sitting above what the home would actually sell for today.

California law gives you a way to fix that. It is called Proposition 8, it has existed since 1978, and most homeowners have never heard of it.

Here is exactly how it works, what it will cost you, and what you need to do before November 30.

The Difference Between Prop 13 and Prop 8

Prop 13 is the one everyone knows. It caps your property tax at 1% of your purchase price (plus local assessments that typically bring the effective rate to around 1.25%), and limits annual increases to 2% per year regardless of what the market does. When prices go up, that is a gift. When prices go down, you are still paying taxes based on your original purchase price.

Prop 8 is the other side of that equation. Passed the same year, it requires the Assessor to temporarily reduce your assessed value if your property's current market value as of January 1, 2026 is lower than your Prop 13 factored base year value.

This is not a permanent change. It is a one-year reduction, and the Assessor reviews it annually. If the market recovers and your value climbs back above your Prop 13 base, the assessment goes back up automatically. But for homeowners who bought at peak prices and are watching values soften, it can mean real money.

The average successful Prop 8 appeal in LA County saves about $1,102 per year. For a luxury home with a $5 million assessed value, the savings could be $5,000 to $20,000 or more annually, depending on how far values have moved.

The Two-Track Appeal System

LA County gives you two tools to contest your assessment. The Assessor strongly recommends filing both at the same time.

Track 1: The RP-87 Informal Decline-in-Value Review

This is the free option. You submit Form RP-87 directly to the Assessor's office. There is no hearing. A staff appraiser reviews your evidence and either accepts a reduction or denies it. The key advantage: the Assessor's office can only reduce your value through this process, never increase it. There is no downside to filing.

The informal review can resolve quickly, sometimes within a few weeks during slower periods. But here is the catch: if the Assessor denies your RP-87, you have no further recourse unless you also filed a formal appeal.

Track 2: The AAB-100 Formal Appeal

The formal appeal goes before the Assessment Appeals Board, an independent body that is separate from the Assessor's office. Filing costs $46 per parcel. If the case is not resolved at the informal level, you get a hearing before the Board and the opportunity to present your evidence and challenge the Assessor's position.

The formal appeal also protects you. If you file only the RP-87 and the Assessor denies it after November 30, you have lost your right to a formal appeal for the year. Filing both tracks simultaneously keeps all your options open.

Who Should File in 2026

You are a strong candidate for a Prop 8 appeal if any of these describe your situation:

You closed on your LA County property in 2024 or 2025 at a price that now looks above current market value. The Prop 13 reassessment at purchase locked in your assessed value at your purchase price. If comparables in your neighborhood have since declined, you may be assessed above market.

You own property in a hillside, coastal, or wildfire-adjacent area where the insurance availability crisis has demonstrably affected values. Beverly Hills, Bel Air, the Hollywood Hills, Malibu, Pacific Palisades, Altadena. These markets have seen real softening.

Your current assessed value is higher than what you think your home would sell for today if you listed it on the open market. That gap is the test. If it exists, you have grounds to file.

You do not need to be certain you will win. The RP-87 is free and carries no risk of a higher assessment. The AAB-100 costs $46 and can be withdrawn before the hearing if circumstances change.

What You Need to File

The Assessor's website at assessor.lacounty.gov has both forms and current instructions. Before you file, gather evidence that documents your home's current market value. The stronger your evidence, the better your chances.

Useful evidence includes: recent comparable sales (ideally within six months and within a mile, for homes of similar size and condition), a current appraisal, listings that did not sell at asking price, documented repair needs or issues that would affect value, and any relevant market data for your specific neighborhood.

You are making the argument that as of January 1, 2026, your home's actual market value was lower than your assessed value. Show comparable sales. Let the numbers do the work.

The Deadline and What Happens If You Miss It

The 2026 filing window opened July 2 and closes November 30, 2026. Both the RP-87 and the AAB-100 must be received or postmarked by November 30. There are no extensions.

If you miss the deadline, the next opportunity is July 2, 2027.

File early if you can. October and November get busy at the Assessor's office. Applications submitted with time to spare get more attention and often resolve faster.

Call 213.974.3211 or visit assessor.lacounty.gov if you have questions about the forms or the process. The Assessor's staff can confirm whether your property is eligible and walk you through the submission process.

How This Fits Into the Broader Tax Picture

If you recently bought your home, you may have already received (or are about to receive) a supplemental tax bill, which is a separate charge that accounts for the difference between the previous owner's assessed value and your new purchase price. That bill is not what a Prop 8 appeal addresses. Those are two different parts of the same system. The supplemental bill covers the reassessment at purchase. The Prop 8 appeal is about what happens when the market moves after you buy.

If you are 55 or older and thinking about selling, there is a related program worth knowing: Prop 19 lets qualifying sellers carry their current assessed value to a replacement home anywhere in California, which can be a significant benefit if you are sitting on a low base year value.

And if you are weighing a sale and trying to understand your full cost picture, the closing costs a seller pays in LA are worth knowing before you list.

Act Before November 30

The Prop 8 appeal process is straightforward, costs nothing or $46 depending on which track you use, and carries no risk of your assessment going up through the informal review. If there is any chance your home's current market value is below your Prop 13 assessed value, the case for filing is clear.

November 30 is the hard stop. If you want to know whether your specific situation makes you a good candidate for an appeal, I am happy to walk through it with you. Reach out and we can talk through what the numbers look like for your property.

Get a free consultation about your LA home's market value today.

Frequently Asked Questions

Can filing a Prop 8 appeal cause my property taxes to go up?

Not through the informal RP-87 review. In that process, the Assessor can only reduce your assessed value, never increase it. The formal AAB-100 appeal is a different proceeding and theoretically allows the Board to consider adjustments in either direction, but in practice the risk of an increase through a Prop 8 filing is very low. If you have concerns about your specific situation, it is worth speaking with a property tax consultant before filing the formal appeal.

What is the difference between my assessed value and my market value?

Your assessed value is the number the LA County Assessor uses to calculate your property tax bill. Under Prop 13, it is based on your purchase price and can only increase by up to 2% per year. Your market value is what a buyer would reasonably pay for your home today in an arm's length sale. A Prop 8 appeal is triggered when your current market value drops below your assessed value.

How long does a Prop 8 appeal take to resolve?

RP-87 informal reviews can resolve in a few weeks to a few months, depending on volume at the Assessor's office. Formal AAB-100 appeals that go to hearing may take longer, sometimes a year or more. Filing early in the July-November window gives you the best chance of a faster resolution.

What evidence does the Assessor's office want to see?

The strongest evidence is recent comparable sales: homes similar to yours in size, condition, and location that closed in the six months before January 1, 2026, at prices below your current assessed value. A certified appraisal is the most persuasive single document. You can also submit market reports, active listings that failed to sell at asking, and documentation of property conditions that affect value.

Do I need a lawyer or consultant to file a Prop 8 appeal?

No. Many homeowners successfully file on their own using the forms at assessor.lacounty.gov. Property tax consultants and attorneys can help with more complex cases or high-value properties where the stakes are larger, and many work on a contingency basis, taking a percentage of the tax savings only if the appeal succeeds. For straightforward cases, the DIY path is reasonable.

About Paul Blair

Paul Blair is a licensed California real estate broker with Grey Square, based in Los Angeles. He has worked with buyers and sellers across LA County for over fifteen years, with a focus on helping clients navigate the financial and legal complexities of residential transactions. CA DRE #01792671. Reach him at greysq.com/contact.