Frequently Asked Questions

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The Proposition 13 Value1 represents the maximum taxable value for your property.

Since the passage of Proposition 13 in 1978, property is assessed at its fair market value as of the date it is acquired. Your purchase price generally becomes the taxable “base value” as of that date. From that point forward the taxable value of your property is limited to no more than a 2% increase per year.2 For example, if you purchase a property which gets assessed at $500,000, the annual taxes would be based on $500,000 the first year, trended to $510,000 ($500,000 x 1.02) the second year, and trended to $520,200 ($510,000 x 1.02) the third year, etc. Also see example below.

In a declining real estate market, the market value of your property may actually be lower than your trended base value. In this case, your property may qualify for a decline-in-value reassessment, temporarily reducing the taxable value to its current market value. Once granted, a decline-in-value reassessment is reviewed annually and may be further reduced, partially restored, or fully restored to its trended base value.

A property was purchased for $500,000. During a three-year period, the real estate market declined and recovered. The property owner filed for a decline-in-value reassessment. The following table shows the trended base value of the property, the market value of the property, and the assessed value of the property. Assuming a 2% annual consumer price index (CPI):

Trended Base Value Market Value Assessed Value
Year 1 $500,000 $500,000 $500,000
Year 2 $510,000 $480,000 $480,000
Year 3 $520,200 $510,000 $510,000
Year 4 $530,604 $550,000 $530,604

In Year 1, the property’s purchase price reflected the market value and was assessed accordingly. In Year 2, the property was granted a temporary decline-in-value to reflect its current market value. In Year 3, the property was partially restored to reflect its rising market value. In Year 4, the property was fully restored to its trended base value (maximum taxable value) even if its market value was now actually higher.

1 Also known as the Proposition 13 assessed value, Proposition 13 trended base value, factored base year value, and trended base year value.
2 The taxable value may increase more than 2% if a transfer of interest or new construction occurs on the property.

If your property has suffered damage of $10,000 or more as a result of a calamity, such as fire or flooding, you are eligible for a reduction in your property taxes. Your property will be immediately reappraised by the Assessor’s Office and you will receive a corrected tax bill or refund. The adjustment and proration of taxes will be based upon the reduction in value from the date of damage to the end of the fiscal year in which the damage occurred, or until the structure is repaired or replaced.

Click here to download the Application for Reassessment of Property Damaged or Destroyed by Misfortune or Calamity. The application must be filed within 12 months of the occurrence of the damage.

If your property is damaged and receives a value reduction due to misfortune or calamity, the value will be reviewed once repairs have been undertaken. If the property is rebuilt in a like or similar manner, your taxes will not be increased beyond their value as it would have been, if the misfortune or calamity had not occurred. You DO NOT lose your Proposition 13 benefits. However, if additional living space or other significant improvements are made in addition to the repair, additional taxes may result.

If you disagree with the assessed value of your property, you should contact the Assessor's Office to request a review of the value.To protect your right to appeal the value of your property you may file a formal appeal with the Assessment Appeals Board.  For Supplemental, Adjusted Supplemental, or Adjusted Property Tax Bills, a formal appeal may be filed within 60 days of either (1) the mailing date printed on a Notice of Assessed Value Change, (2) the date of mailing printed on the tax bill, or (3) the postmark date for the tax bill, whichever is later. For the "Regular Assessment Roll," a formal appeal may be filed from July 2 through November 30 of the particular roll year.

Appeals must be filed with the Assessment Appeals Board, Room B-4, Kenneth Hahn Hall of Administration, 500 W. Temple Street, Los Angeles, CA 90012-2770. Visit the Assessment Appeals Board website for more information and to file your appeal online, or call 213.974.1471 to request an application by phone.

Please view this video to learn more about the assessment appeals process.

State law requires the Assessor to reappraise property upon change in ownership or completion of new construction. The supplemental assessment reflects the difference between the new value and the old value. Please see Supplemental Assessments for additional information.

To inquire about your refund, please contact the office of the Auditor/Controller. On their inquiry form, please be sure to include specific information such as your name, property address and if possible the Assessor Identification Number.

For property tax purposes you will need to know and use your AIN. The Assessor's Identification Number or AIN is the main indexing system used for property tax purposes. The AIN is a ten-digit number assigned to each piece of real property and is used on tax bills and correspondence to identify real property. The ten-digit AIN (1234-056-789) is made up of a four-digit Mapbook Number, a three-digit Page Number and a three-digit Parcel Number. You can locate your AIN various ways:

  • The AIN can be found on your deed
  • The AIN can be found on your "Annual Property Tax Bill” or “Supplemental Property Tax Bill”
  • The AIN can be found by entering your property address on the “Property Maps and Data” link or the “Property Sales and Maps” quick link from our internet homepage
  • The AIN can be found on your title report (which you received when you acquired title insurance)
  • The AIN can be found by contacting us at (213)974-2111, or toll free at (888)807-2111, option 6, or any of the Assessor’s Office Locations

You can also email us at for assistance.

The Auditor/Controller website will help you to find contact information concerning Direct Assessments found on your County of Los Angeles Property Tax Bill.