Frequently Asked Questions
The Alameda County Assessor’s Office has compiled answers to the most commonly asked questions about property assessment, tax relief programs, and our services. Select a topic below to learn more.
Property Assessment
How is my property assessed?
Under California’s Proposition 13, property is assessed at its fair market value at the time of purchase (the “base year value”). Each year, the assessed value may increase by no more than 2% (the Consumer Price Index adjustment), unless there is a change in ownership or new construction.
Why did my assessed value increase by more than 2%?
There are several reasons your assessed value may increase by more than 2%, including a change in ownership, completion of new construction, or restoration of a previously reduced value (Proposition 8 restoration). For more information, visit our page on About Property Assessment.
What is a supplemental assessment?
When a property changes ownership or new construction is completed, the Assessor’s Office issues a supplemental assessment reflecting the difference between the old and new assessed values. This may result in an additional tax bill or a refund. Learn more on our Supplemental Assessment page.
Decline in Value (Proposition 8)
What if my property is worth less than its assessed value?
If the current market value of your property is less than its assessed value, you may be eligible for a temporary reduction under Proposition 8 (Decline in Market Value). The Assessor’s Office reviews values annually and may automatically reduce assessments where market data supports a lower value. You can also request an informal review. Visit our Decrease Your Assessment page for details.
Assessment Appeals
How do I appeal my property assessment?
If you believe your property’s assessed value is higher than its fair market value, you may file an Assessment Appeal Application with the Alameda County Assessment Appeals Board. The filing period is typically July 2 through September 15 each year (or November 30 for supplemental assessments).
豁免
What is the Homeowners’ Exemption?
The Homeowners’ Exemption reduces the assessed value of your principal residence by $7,000, saving approximately $70-$80 per year in property taxes. Visit our 豁免 page to learn more and apply.
What is the Disabled Veterans’ Exemption?
Veterans rated 100% disabled by the VA may qualify for a significant property tax exemption. See our 致退伍军人 page for eligibility details and how to apply.
Change in Ownership
What triggers a change in ownership reassessment?
A change in ownership typically occurs when property is transferred from one owner to another, including sales, gifts, inheritance, and certain trust transfers. Some transfers are excluded from reassessment, such as interspousal transfers and certain parent-child transfers under 提案19.
What do I need to report when a property owner dies?
The death of a property owner must be reported to the Assessor’s Office within 150 days. Visit our 死亡相關資訊 page for required documents and guidance.
商業不動產
What is business personal property?
Business personal property includes furniture, fixtures, equipment, computers, and other tangible assets used in a business. Business owners are required to file an annual property statement (Form 571-L) by April 1 each year. Visit our 商業不動產 page for details.
Parcel Maps
Where can I find parcel map information?
Visit our 地籍圖常見問題 page or use the Assessor Parcel Viewer to search and view parcel maps online.
聯絡我們
Can’t find the answer you’re looking for? Contact us:
- Phone: (510) 272-3787
- Main Office: 1221 Oak Street, Room 145, Oakland, CA 94612
- Public Lobby Hours: 9:00 AM to 4:30 PM, Monday through Friday (except holidays)