Property tax assessment in California confuses many homeowners, largely because of Proposition 13, the landmark 1978 ballot measure that reshaped how properties are taxed. The most common question is simply how the county arrives at a property’s assessed value. Under Proposition 13, a property’s taxable value is based on its purchase price at the time of acquisition, known as the base year value, plus an annual adjustment for inflation capped at 2 percent per year. This means two identical homes on the same street can carry very different tax bills depending on when each was last sold.

People often ask what the base year value actually means. The base year is the year a property was purchased or newly constructed, and the assessed value starts at the price paid in that transaction. From there, the county assessor may increase the value by up to 2 percent each year, but never more, even when the market surges. If the market drops, the assessed value does not automatically fall, though homeowners can request a temporary reduction through a decline in value review when the market value drops below the assessed value.

Another frequent question concerns reassessment. A property is generally reassessed only when it changes ownership or undergoes new construction. Certain transfers between family members, such as from parent to child under specific conditions, may avoid reassessment, and there are limited exclusions for transfers between spouses and for some seniors and disabled homeowners. Buyers often ask whether they can appeal their assessed value. Yes, homeowners can file an assessment appeal with the county assessment appeals board during the filing period, usually between July and September, though the deadline varies by county.

Prospective buyers frequently ask whether they will inherit the seller’s low tax base. Generally no, because a sale triggers reassessment at the new purchase price, which can sharply raise the tax bill. This is why long-time owners often pay far less than recent buyers. Homeowners also ask about the homeowners’ exemption, a modest reduction of around seven thousand dollars off the assessed value for an owner-occupied principal residence, which must be filed with the county.

Finally, many wonder whether Proposition 13 can ever be changed. It can be amended by voters, and recent measures have adjusted rules for certain transfers and for inherited properties, but the core structure of a base year value with a 2 percent annual cap remains intact. Understanding these basics helps homeowners anticipate their tax bills and know when to contact the assessor or file an appeal.

A closer look is at read about reassessment.