Property Taxes in Port Costa, California
Median Port Costa, California effective property tax rate: 1.73%, significantly higher than the national median of 1.02%, and higher than the California state median of 1.21%.
Median Port Costa, California home value: $421,753
Median annual Port Costa, California tax bill: $7,139, $4,739 higher than the national median property tax bill of $2,400.
How are property taxes in Contra Costa calculated?
Property taxes in Port Costa, California are calculated based on the tax assessed value, which is often lower than the actual market value due to property tax exemptions such as the homestead or senior exemption.
Understanding Port Costa's property tax system, exemptions, and reduction opportunities can lead to significant savings. Regardless of where you live in Port Costa, knowing local tax details benefits homeowners and investors.
Last Updated April 13, 2026
How Does the Port Costa Property Tax Calculator Work?
Use this Port Costa property tax calculator to estimate your annual tax bill. Enter your property's assessed value and our calculator applies Port Costa's median effective tax rate of 1.73% — based on actual property records in Contra Costa County — to generate your estimate.
Enter your property's estimated assessed value — the figure the local assessment system uses to calculate your bill, which reflects any exemptions you hold and is typically lower than your home's market value. Our calculator applies Port Costa's median effective rate across all local levies, providing a more accurate estimate than applying a single county rate.
Your bill may vary by ZIP code within Port Costa: rates range from 1.73% in 94569 to 1.73% in 94569, primarily due to differences in school district levies and local assessment districts.
Port Costa's median property tax rate is higher than the California median rate of 1.21%, and the median property tax bill of $7,139 is higher than the national median property tax bill of $2,400. If your estimate is higher than expected, Ownwell can appeal your Port Costa assessment — you only pay if we save you money.
About Port Costa Property Taxes
About Property Taxes in Port Costa, Contra Costa, California
Port Costa’s median effective property tax rate of 1.73% is higher than the California state median of 1.21% and higher than the national median of 1.02%. This rate reflects the Contra Costa County base levy combined with local school district levies and Mello-Roos Community Facility Districts that vary by subdivision throughout the city.
Property tax rates are not uniform across Port Costa. Homeowners in ZIP code 94569 carry a median effective rate of 1.73%, while those in 94569 pay 1.73%. This spread — 0 percentage points across the same city — reflects how school district boundaries and local assessment districts are drawn across Contra Costa County. Understanding which part of Port Costa you live in can make a meaningful difference to your annual tax bill.
Port Costa homeowners who believe their assessed value is too high can file a formal appeal with the local Tax Assessor before December 1, 2026.
If your estimated bill above seems higher than expected, Ownwell can review your assessment and protest on your behalf. You only pay if we save you money.
Property Tax Rates Across Port Costa, Contra Costa County, California
As noted earlier, local government entities set tax rates, which can vary widely within a state.
Why? Because annually, each county estimates its required budget to provide services and divides that by the total value of all taxable property within its jurisdiction. This calculation results in the property tax rate.
While there are votes and laws involved in setting tax rates and budgets, in a nutshell, this is the annual process.
Below, you can compare Port Costa's effective property tax rate to other cities in California and the median property tax rates in California and the U.S.
Our median effective property tax rate (tax bill ÷ assessor's market value) accounts for exemptions and deductions, making it more accurate than the general median tax rate, which is the midpoint of statutory rates before adjustments.
Median Effective Port Costa Tax Rate
1.73%
Our median effective property tax rate (tax bill ÷ assessor's market value) accounts for exemptions and deductions, making it more accurate than the general median tax rate, which is the midpoint of statutory rates before adjustments.
Median Effective Contra Costa County Tax Rate
1.31%
Median Effective California Tax Rate
1.21%
Median Effective United States Tax Rate
1.27%
Property Tax Rates Across Port Costa, Contra Costa County, California
| Zip | 10th Percentile | 25th Percentile | Median Tax Rate | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 94569 | 1.42% | 1.53% | 1.73% | 2.44% | 5.63% |
Source: Ownwell
Save on Your Property Taxes and More With Ownwell
$774
Average Annual Tax Savings
Property Tax Assessment Values Across Port Costa, Contra Costa County, California
When examining property taxes in Port Costa, California, understanding the distinction between "market value" and "assessed value" is crucial.
The market value is what a willing buyer would pay to a willing seller in an open and competitive market, often influenced by location, property condition, and economic market trends. The Contra Costa County assessment office estimates the market value for tax purposes.
The assessed value is the market value minus any applicable exemptions or limits determined by local laws and offerings. The tax assessed value is the figure used to calculate your property taxes or the amount multiplied by your tax rate to get your tax bill.
Assessment notices:
In Contra Costa County, assessment notices are sent in October each year. They'll typically reach your mailbox by the middle of October.
Each property owner receives an assessment notice that contains both the market value and assessed value, along with an estimate of your property tax bill. By providing insights into how assessed and market values are determined, this section helps property owners navigate their tax responsibilities and understand the valuation processes affecting their property taxes in Port Costa.
For example, the median home price in Port Costa is $421,753, with tax bills ranging significantly across the county. 94569 has the highest median home price at $421,753.
Property Tax Assessment Values Across Port Costa, Contra Costa County, California
Source: Ownwell
$153,114
$1,176,704
$2,200,294
Median Port Costa Market Value
$421,753
Median Contra Costa County Market Value
$530,390
Median California Market Value
$427,605
Median United States Market Value
$274,101
Property Tax Assessment Values Across Port Costa, Contra Costa County, California
| Zip | 10th Percentile | 25th Percentile | Median Home Price | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 94569 | $69,463 | $220,841 | $421,753 | $565,658 | $670,969 |
Source: Ownwell
Save on Your Property Taxes and More With Ownwell
$774
Average Annual Tax Savings
Property Tax Bills Across Port Costa, Contra Costa County, California
Property tax bills in Port Costa are based on the assessed value of a home, not its market price alone. Local tax rates are applied to that assessed value, and the final bill can also reflect exemptions and other local factors. With a median home price of $421,753, homeowners in this area often face bills that are well above the national median property tax bill of $2,400.
For many homeowners, the tax bill is a major part of annual housing costs. In Port Costa, the 25th percentile tax bill is $5,086, the 75th percentile is $8,654, and the 90th percentile is $9,561. The median tax bill in ZIP code 94569 is $7,139, showing how quickly property taxes can add up.
Ownwell helps homeowners lower property tax bills by reviewing assessments for errors and identifying opportunities for savings. If your home is overassessed, an appeal can reduce what you owe and help keep more money in your pocket each year.
Property Tax Bills Across Port Costa, Contra Costa County, California
Source: Ownwell
$3,003
$13,751
$24,499
Median Port Costa Tax Bill
$7,139
Median Contra Costa County Tax Bill
$6,979
Median California Tax Bill
$5,134
Median United States Tax Bill
$3,209
Property Tax Bills Across Port Costa, Contra Costa County, California
| Zip | 10th Percentile | 25th Percentile | Median Tax Bill | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 94569 | $3,601 | $5,086 | $7,139 | $8,654 | $9,561 |
Source: Ownwell
Save on Your Property Taxes and More With Ownwell
$774
Average Annual Tax Savings
Don't miss the deadline to appeal!
Dates | |
|---|---|
| Property Valuation Date | January 1 |
| Appeal Deadline | November 30 |
| Tax Bill | |
| Issued | October 1 |
| Due Date #1 | December 10 |
| Due Date #2 | April 10 |
Links | |
|---|---|
| Contra Costa Tax Assessor | |
| Website | www.contracosta.ca.gov |