Market Value vs Assessed Value in California

By Doug Van SoestDoug Van SoestUpdated
Comparison of assessed value vs market value of property

Market value is the price a willing buyer and seller would agree to in the current market, supported by comparable sales and the property’s actual condition. Assessed value is the taxable value the county places on the property under California property-tax rules, and it does not set the sale price.

Start with the decision you’re making:

  • Setting a sale price: Use current comparable sales and your home’s condition.
  • Checking property taxes: Use the county’s taxable assessed value and the charges on your bill.

California’s Proposition 13 can keep a longtime owner’s taxable value well below market value. A low assessment does not mean you have to sell for that amount.

Buyers and appraisers use market evidence when they evaluate a sale. The assessed value belongs in the property-tax analysis, and long-term owners often see a large gap between those two numbers.

What Assessed Value Is in California

How Prop 13 Works

After a qualifying change in ownership, the assessor generally establishes a base-year value at fair market value. Proposition 13 limits its annual inflation adjustment to the lower of the California Consumer Price Index or 2%. That adjusted amount is called the factored base-year value.

The 2% limit does not cover every increase. A temporary Proposition 8 decline-in-value assessment can rise by more than 2% as the market recovers, up to the factored base-year value. A new ownership change or assessable construction can change that ceiling.

For illustration, a property bought for $185,000 in 1999 could have a factored base-year value far below its current sale price. The actual taxable value depends on the annual inflation factors, later ownership changes, new construction, exclusions, and any Proposition 8 reductions.

The county number is built for the tax bill. When you’re pricing a sale, start with what similar homes are selling for now, not what your assessment has grown to over the years.

The assessor uses fair market value when a qualifying change in ownership or completed new construction creates a new base-year value, and a partial transfer or improvement may reassess only part of the property. The contract price is evidence of value, but it is not a rule that locks every assessment to the number printed on the closing statement.

Prop 19 and Parent-to-Child Transfers

Proposition 19 changed California’s parent-to-child transfer rules beginning February 16, 2021. Under the former rules, a qualifying principal residence and up to $1 million of taxable value of other real property could receive exclusions, subject to the requirements in effect for that transfer.

For the Proposition 19 family-home exclusion, check these requirements with the assessor:

  • The home: It must qualify as the parent’s principal residence.
  • The child’s use: An eligible child must make it a principal residence within one year of the transfer and file for the homeowners’ or disabled veterans’ exemption within that year.
  • The exclusion claim: File the separate transfer-exclusion claim within three years or before a transfer to a third party, whichever comes first. Notice-based exceptions or late-claim rules may apply; check the assessor’s deadline for your case.

At least one eligible recipient must continue using the home as a principal residence to maintain the exclusion. A rental or other nonqualifying transfer generally does not preserve the parent’s taxable value under this family-home rule. See the BOE’s current transfer guidance for filing exceptions and later changes in occupancy.

There is also a value test even for a qualifying principal residence. The adjusted exclusion amount is $1,044,586 for transfers from February 16, 2025 through February 15, 2027.

Example: a qualifying family-home transfer

This hypothetical example shows why qualifying for the exclusion does not always preserve the entire old taxable value.

  • Parent’s taxable value: $300,000.
  • Market value at transfer: $1,800,000.
  • Applicable exclusion amount: $1,044,586.
  1. Find the value limit: $300,000 + $1,044,586 = $1,344,586.
  2. Find the excess: $1,800,000 − $1,344,586 = $455,414.
  3. Add that excess to the old taxable value: $300,000 + $455,414 = $755,414.

The new taxable value would be $755,414 using these assumptions. The assessor’s actual values and every exclusion requirement still control.

For an inherited rental, check the assessor’s change-in-ownership determination and expected tax bill before deciding whether rental income covers the costs.

What Market Value Means

How Market Value Gets Established

I worked in residential appraisal for seven years beginning in 2003 and began investing in 2008, and recent comparable sales were the starting point on a value question. The appropriate date range and distance depend on the property, neighborhood, market conditions, and available evidence rather than one fixed rule.

An automated estimate can provide a rough directional read, but it is not a substitute for verified property facts and comparable sales. Lenders, appraisers, agents, and buyers may consult different tools, but a supportable value opinion has to account for the actual property, relevant market evidence, and the purpose of the analysis.

Why It Moves Around

The market number responds to financing conditions, inventory, buyer demand, and recent sales. Older transactions may need time adjustments or carry less weight, but the appraiser or agent may expand the date range when few truly comparable properties have sold.

By comparison, the factored base-year value usually changes much more slowly. Those two numbers can end up really far apart if you’ve owned the place a long time.

How Wide the Gap Gets in Southern California

Same house, two different jobs for the numbers

  • Taxable assessed value: $300,000 in this hypothetical example, used for the property-tax calculation.
  • Market value: $580,000 supported by current market evidence in this example, used when considering a sale.

The $280,000 difference is not a discount you owe a buyer or an amount of equity. Neither the original purchase price nor an assumed annual increase establishes your home’s actual values.

If you price the house from the tax bill alone, you can miss what buyers would actually pay.

Check the Property Behind the Estimate

An automated estimate and a tax assessment answer different questions, and neither replaces a property-specific sale analysis. Compare relevant closed sales, verify condition, and ask how each adjustment affects the value opinion.

When Each Number Comes Up

Your Tax Bill

If you’re trying to understand the property-tax bill, start with the taxable assessed value. California’s base levy is 1%, with voter-approved debt, direct assessments, and other charges added according to the property and jurisdiction.

Some properties also carry Mello-Roos special taxes or other direct assessments. Read the current bill in three parts:

  • Taxable assessed value: The amount used to calculate value-based property taxes.
  • Tax rates: The base levy plus applicable voter-approved debt rates.
  • Separate charges: Special taxes or assessments that a single statewide rate will not capture.

If the assessment looks too high, check the value on the correct assessment date, not just today’s asking prices.

Appealing Your Assessment

The appeal goes to the county appeals board, which is separate from the assessor’s office. The BOE’s residential appeal guide explains the process.

  1. Identify the assessment: A regular decline-in-value appeal uses January 1 of that assessment year, not today’s value.
  2. Check the filing window: Regular appeals run July 2–September 15 or November 30, depending on the county. Supplemental appeals have separate deadlines; use your notice and the county clerk’s instructions.
  3. Gather the right evidence: Use comparable sales relevant to the valuation date. Sales more than 90 days after that date cannot be admitted.

Keep paying your tax bill on time. Filing an appeal does not suspend payment deadlines.

If the board grants the appeal, the county applies the decision through its assessment and tax processes. The effect and any refund depend on the assessment year, appeal type, and county records.

When You’re Selling or Refinancing

The assessed value does not establish the sale price or the value conclusion in a refinance appraisal. A lender’s appraiser develops an opinion of market value from the relevant market evidence for that assignment.

Buyers may consider many numbers, including the tax assessment, but it is not a binding measure of what they should offer. Compare the condition and terms of actual sales instead of treating the tax roll as a price list.

After a qualifying change in ownership, the assessor generally establishes a new base-year value at fair market value as of that date. The sale price can support that value, but exclusions, partial transfers, unusual deal terms, and other evidence can keep the assessed value from simply matching the contract price.

How to Find Out What Your Home Is Worth

Getting a Formal Appraisal

A licensed appraiser can provide a documented, independent opinion of value for a defined purpose and effective date. A lender may still order its own appraisal and is not required to accept a report commissioned by the owner.

When a lender requires an appraisal for refinancing, it generally orders the report through its own process. Our fair market value guide explains the difference between an appraisal, a market analysis, and a purchase offer.

Running Your Own Comps

If you’re trying to get an initial sense of value, review reliable records of recent closed sales and ask an agent or appraiser to explain the strongest comparables. Public portals can be useful, but confirm the property facts and sale terms before relying on them.

For each proposed comparable, check:

  • Sale status and date: Start with closed sales. Active and pending listings provide context, not proof of a completed price.
  • Property match: Compare location, size, layout and condition, rather than relying on price per square foot alone.
  • Differences and terms: Ask how repairs, improvements or seller credits affect the comparison.

The proper date range depends on how quickly the market is moving and how many comparable properties are available.

A real estate agent may provide a comparative market analysis as part of discussing a possible listing. Review the selected comparables and adjustments rather than accepting the conclusion without seeing the supporting sales.

Your property-tax assessment is not your income-tax basis. For capital gains tax implications, the calculation generally compares sale proceeds after selling expenses with adjusted basis, your cost for tax purposes after applicable adjustments.

The IRS exclusion for primary residences covers many situations, but not all. Have a CPA check the calculation and eligibility before closing.

Supplemental Assessments After Improvements

Qualifying completed new construction can trigger a supplemental assessment, while excluded work and ordinary maintenance do not automatically do so just because a permit exists. The assessor generally values the assessable new portion at current market value and leaves the unaffected portion on its existing base.

Example: added construction value, not the contractor’s bill

  1. Assume the assessor adds $180,000 of taxable new-construction value.
  2. At the base 1% levy, $180,000 × 1% = $1,800 of additional annual tax before voter-approved debt and other charges.

That is an annual illustration, not necessarily the supplemental bill amount. Supplemental bills depend on the completion date and applicable proration; one or two bills may result from that event.

Sellers who recently completed assessable new construction may not have received every supplemental bill before a sale. Review the assessor notices and escrow proration because an outstanding or later-issued bill can affect the parties even if it was not in the first payment estimate.

Market Value vs. Assessed Value: Common Questions

Which number do buyers actually use when they make an offer?

Buyers generally consider comparable sales, condition, and their intended use. A tax assessment does not establish the negotiated sale price, even when someone brings it into the discussion.

A lender’s appraisal also develops an opinion of market value from relevant market evidence. The assessed value serves the property-tax system and may follow a very different path.

Why is my assessed value so much lower than what my house would sell for?

Under Proposition 13 the assessor generally establishes a base-year value at fair market value after a qualifying change in ownership and applies an annual inflation factor capped at 2%. Market value tracks what buyers are paying now, while exclusions, new construction, partial reassessments, and Proposition 8 reductions can cause the taxable value to follow a different path.

Can I lower my property tax bill if my assessment seems too high?

You can appeal, but the deadline and valuation date depend on the type of assessment. The regular decline-in-value filing period runs from July 2 to September 15 or November 30 depending on the county, while a supplemental-assessment appeal generally uses a different deadline tied to the notice or bill.

The county appeals board is separate from the assessor, and the evidence must address the correct valuation date. Check the current county deadline and BOE instructions before filing.

If You’re Thinking About Selling

If you’ve owned your home for years in Southern California, its market value may be significantly above its assessed value. Keep these two calculations separate:

  • Equity: The home’s market value minus mortgages and other liens against it.
  • Estimated net sale proceeds: The actual sale price minus payoffs and selling expenses. Any income tax due needs its own calculation.

For an offer on the property in its current condition, we can explain our comparable sales and repair assumptions. Our purchase offer is not an independent appraisal or a county assessment.

If a direct sale is one of your options, we can evaluate the house and explain the price we would offer. We buy in San Diego, Orange, San Bernardino, Riverside, and Los Angeles counties. Compare that offer with an independent market analysis before deciding what works for you.

Give us a call at (951) 331-3844 or request a cash offer here.

If you’re still weighing your options, the cash sale comparison puts commission and carrying costs on the same side of the ledger so you can see what the net difference looks like.

For inherited property, review both property-tax reassessment and income-tax basis; they are separate calculations. The inherited house sale guide covers the sale and authority questions.

Doug Van Soest worked in residential appraisal for seven years beginning in 2003 and co-founded SoCal Home Buyers with his wife Andrea Van Soest, CA DRE #01505854. Together they have closed over 400 transactions across Southern California.