LA County Reminds Property Owners: Decline-in-Value Review Deadline Is November 30

Los Angeles County property owners got a nudge this week from the Assessor's office: the deadline to file a Decline-in-Value review application is November 30, and owners who think their property's market value has fallen below its assessed value as of January 1, 2026 should start the paperwork now.

The reminder, released Sept. 24, is a follow-up to the notice sent when the filing window first opened on July 2. Applications are accepted from July 2 through November 30 each year. To file, owners complete the Decline-in-Value Review Application (Form RP-87), available on the Assessor's Decline-in-Value webpage under the Forms tab, and it can be submitted online.

Here's how the program works: under California's Proposition 8 (1978), when a property's market value drops below its assessed value, the owner can get a temporary reduction in assessed value — which lowers the property tax bill for that year. Prop 13's base-year value still applies underneath, so the reduction is temporary: as market values recover, the assessed value can climb back up, sometimes by more than the usual 2% annual cap.

The best supporting documentation is information on comparable sales near the property — ideally two comparable sales that closed as close to January 1, 2026 as possible, and no later than March 31, 2026. The Assessor notes that applications submitted without comparable sales will still be accepted and processed.

For South Bay homeowners, this is worth a look precisely because the market has been uneven: prices have held broadly, but individual pockets and property types (especially condos and townhomes) have softened. If your January assessed value looks high relative to what comparable homes were selling for around the start of the year, a filing before November 30 costs nothing but your time — and the reduction is reflected on the annual tax bill for the fiscal year beginning July 1.

Source: LA County Assessor's Office release (Sept. 24, 2026), via Ramiro & Erica Rivas — https://ramiroanderica.com/la-county-decline-in-value-assessment/

Curious what these market shifts mean for your home? Get a free personalized valuation →