Written by: David Milner, Managing Director, Property Tax
California’s property tax assessment appeals system operates unlike any other state. Instead of reassessing properties on a set schedule, values typically rise modestly each year—capped by inflation—and are only reset to full market value when certain events occur, like a sale or major construction.
These rules limit how and when values change, but they also create challenges, especially for commercial taxpayers. Knowing when and how to appeal property tax assessments in California can prevent long-term overpayment and impact overall portfolio performance, but many businesses overlook opportunities to challenge assessed values and reduce liability.
Proposition 13 vs. Proposition 8
This system stems from two pivotal measures passed in 1978. While these two measures work together, they affect California property tax assessments in different ways. Understanding the distinction is key to knowing when and how to appeal:
- Proposition 13 caps annual increases in assessed value at 2% or the California consumer price index (CCPI), whichever is lower—unless a triggering event resets the value to market through a full reassessment.
- Proposition 8 allows taxpayers to request a reduction in assessed value when market value falls below it. These reductions apply on a one-year basis and must be filed annually.
While these rules can offer long-term stability, they also create risk, particularly for commercial properties. Assessed values continue to rise each year, but the system does not automatically account for market decline or sector-specific downturns. Without action from the taxpayer, overassessment can persist for years—especially in underperforming asset classes.
Prop 13 Reassessments
County assessors do not conduct planned reassessments. Instead, reassessments occur only when specific events take place; typically involving ownership changes or property improvements. When a triggering event occurs, the property is reassessed at full market value, and the 2% cap applies to the new assessed value.
What Triggers a New Valuation in California?
These events eliminate the annual cap and trigger a full or partial reassessment to market value:
| Triggering Event | Common Impact |
|---|---|
| Change in Ownership | Full reassessment to current market value |
| New Construction/Renovation | Reassessment of new or improved portion |
| Legal Entity Transfer | Reassessment if controlling interest changes hands |
| Subdivisions or Mergers | Parcel changes may prompt new valuation |
When reassessed, a property is valued at full market value as of the lien date following the event. These step-ups can substantially increase tax liability, particularly in appreciating sectors. California taxpayers should have any reassessed values reviewed by a property tax professional to identify potential assessment appeal opportunities and avoid overpaying property taxes.
Proposition 8 Appeals
Even without a reassessment, taxpayers may still qualify for a one-year reduction under Proposition 8, but only if they proactively file. Prop 8 applies when a property’s market value falls below its current assessed value—a common occurrence in underperforming sectors.
Sectors presently affected include:
- Office (especially downtown and suburban Class B/C)
- Hotels and hospitality
- Retail centers and malls
- Senior living and healthcare facilities
These appeals must be filed proactively every year to be applied; they are not automatic. Annual relief under Prop 8 can significantly reduce overpayment when market values decline.
If your property’s market value has declined, consult a property tax professional experienced in Prop 8 reductions to assess whether an appeal could reduce your liability.
Key Reassessment Facts
| Valuation (Lien) Date | January 1, 2026 |
| Tax Years Affected | 2026-2027 |
| Jurisdictions Affected | California (all 58 counties) |
| Assessment Notices Expected | June-August 2026 (varies by county) |
| Appeal Deadlines | July 2-September 15, 2026 (many counties) July 2-November 30, 2026 (select counties) |
Why Early Preparation Matters for California Property Tax Appeals
In California, many reassessments occur following planned events like acquisitions, improvements, or entity restructuring. But without early evaluation, the tax impact of those events can be surprising, and opportunities to respond may pass quickly. Likewise, Proposition 8 relief must be re-evaluated annually and supported by market data—a step many taxpayers miss, often leaving potential savings on the table. Early planning for California property tax appeals helps ensure:
- Tax impacts from planned activity are reviewed in advance
- Prop 8 opportunities are accurately identified and documented
- You’re ready to respond when notices arrive or appeal windows open
DMA supports and guides taxpayers through the California property tax assessment appeals process across all 58 counties—minimizing risk and maximizing savings.
Schedule a No-risk California Property Tax Review
Whether your property has been reassessed due to a recent transaction or may qualify for Proposition 8 relief, DMA’s California property tax specialists can evaluate your assessment and identify opportunities to reduce tax liability. Review your valuation before appeal deadlines pass and assessment errors become embedded for years to come.
Connect with DMA’s California property tax experts to review your portfolio, identify overassessment risk, and uncover potential savings. We’ll work together with your team to compare your projected or actual assessment to market evidence and tell you whether an appeal makes sense.
This website content should be used for general informational purposes only, and not as a substitute for consultation with professional tax, legal, or other competent advisors.
Before making any decision or taking any action based upon information contained on this website, you should consult with a DMA professional.