How does Proposition 13 affect my property taxes in LA County?

Prop 13 limits your assessed value to the purchase price plus a maximum 2% annual increase. You can only appeal if your market value drops below this factored amount.

What is the filing deadline for LA County assessment appeals?

September 15 for regular roll assessments. November 30 for supplemental assessments. These deadlines are strict.

Can I appeal a supplemental assessment?

Yes. If you recently purchased your home and the supplemental assessment seems too high, you can appeal by November 30.

How long does an LA County appeal take?

Due to high volume, LA County appeals can take 12-24 months to be heard. File as early as possible.

Guides/California/Los Angeles County

Los Angeles County, California

How to Appeal Property Taxes in Los Angeles County (2026)

Appeal Deadline

November 30 (for regular roll assessments; supplemental/escape: 60 days from notice)

County Assessor Appeal Forms

Overview

Los Angeles County is the largest county in the nation with approximately 2.4 million parcels. Under California's Proposition 13, your property's assessed value is typically based on the purchase price and can only increase by up to 2% per year. However, if your property's market value has dropped below its assessed value (a 'decline in value'), you can file for a temporary reduction. This is particularly relevant after market downturns.

Step-by-Step Appeal Process

Check if your current assessed value exceeds your property's current market value

If so, file an Assessment Appeal Application (Form ADA-001) with the Assessment Appeals Board

File by September 15 for the regular assessment roll, or November 30 for supplemental assessments

Gather comparable sales showing your property's current market value is below the assessed value

Attend your scheduled hearing (or waive your right to appear if submitting evidence only)

Receive the Appeals Board decision

What Evidence Do You Need?

Comparable sales showing current market value below assessed value

Independent appraisal from a California-licensed appraiser

Market data showing decline in your specific area

Evidence of property damage or condition issues affecting value

Common Reasons for Successful Appeals

Market value has declined below the Prop 13 factored base year value

Supplemental assessment from a recent purchase or construction is too high

Property damage (fire, earthquake, etc.) has reduced value

Incorrect property characteristics in county records

Neighborhood factors negatively affecting value (new freeway, commercial development)

Tips for Success

1Under Prop 13, your base year value increases by no more than 2% per year — appeals are for when market value drops below this

2The LA County Assessor offers a free online Value Decline Review — try this before filing a formal appeal

3If your market value rebounds, the county can restore the assessed value up to the Prop 13 limit

4Appeals in LA County can take 12-18 months due to backlog — file early

Frequently Asked Questions

Check Your Assessment in Los Angeles County

Enter your address to see if you're overpaying and get a professional appeal packet for $49.

Free Assessment Check

This guide is for informational purposes only and does not constitute legal advice. Deadlines and procedures may change. Always verify current information with your county assessor.