How Much Are Property Taxes in Contra Costa County, California?

A lot of our readers and clients have questions about the cost of living here in Contra Costa County. One of the most common questions we get is how much property taxes are.

The short answer: The current property tax rate for most homes located within the county is 1% plus any general obligation bond tax rates. This means it can vary slightly from one city to the next. Even so, the average Contra Costa County property tax rate is somewhere in the low 1% range.

Related: Home buyer closing costs in Contra Costa

What Are Property Taxes?

Property taxes are annual taxes paid by homeowners based on the assessed value of their property. In California, that assessed value is usually established when you purchase the home and is governed by Proposition 13.

Under Prop 13:

• The base property tax rate is 1% of assessed value
• Your assessed value can typically increase by no more than 2% per year
• The property is reassessed to market value when it changes ownership

In simple terms, when you buy a home in Contra Costa County, your purchase price generally becomes your new assessed value. From there, the county applies the 1% base tax rate plus any local bond assessments tied to your property’s tax rate area.

Property taxes are paid to the county, usually in two installments each year. If you have a mortgage, your lender will typically collect property taxes monthly as part of your mortgage payment and pay them on your behalf through an escrow account.

Understanding how this works is important because property taxes are a permanent part of your monthly housing cost.

The Property Tax Rate in Contra Costa County Explained

The property tax rate in Contra Costa County is comparable to most other counties across the state of California. They typically come in somewhere around 1%, plus any increases for local bond measures.

According to the Contra Costa County Auditor-Controller’s website:

The tax rate consists of the 1% general tax plus any general obligation bond tax rates. General obligation bond tax rates are determined by the annual bond debt service requirements and the assessed valuations of the districts that issued the bonds. These rates may change each fiscal year depending on the debt service requirements and assessed valuations of the districts.

So you have the general property tax rate of 1%, which applies to nearly all homes in the county. And on top of that, you might have a “markup” for any general obligation bonds in the area where the property is located.

General obligation bonds are common in cities and counties across the U.S. These municipal bonds are secured by a state or local government pledge to use tax revenues and other resources to repay bondholders.

In Contra Costa County, most of these voter-approved bonds are used to provide funding for infrastructure projects like school construction and renovation. This is true for many counties across the U.S. Property taxes are commonly used to fund local school-related projects, once approved.

There are no homeowner exemptions for paying these bonds, just as there are no exemptions for paying property taxes in Contra Costa County.

If you’d like to know the exact rate for the area where you plan to buy a home, visit the county’s Auditor-Controller website (Google it) and look for the “Property Tax Publications.” You’ll need to know the “tax rate area” number where the home is located, which you can also find on the Auditor’s website.

Average Property Taxes Based on Local Home Prices

We talked about the Contra Costa County property tax rate above. But what about the average amount of taxes paid by homeowners in the area?

While the county doesn’t publish a single property tax calculator for every city, homeowners can still estimate their taxes using the following:

• The home’s assessed (or median) value
• The total property tax rate for the area, including any local bond measures

To calculate a rough average for Contra Costa County, we can use the countywide median home price and a typical tax rate of 1.25%. As of early 2026, the median home value in the county was around $766,060 (according to Zillow). Applying a property tax rate of 1.25% (typical for many Contra Costa areas) would give us an annual payment of $9,575.

Again, this is just a ballpark figure based on countywide price data. Your tax bill could be lower or higher based on several factors. But this does give us some sense of the average property taxes paid by homeowners in the area.

Related: Who pays closing costs in Contra Costa?

Where Does the Money Go?

Property taxes provide funding for a wide range of county projects, services and operating costs.

As mentioned above, these funds are often used to cover the cost of public school construction, rehab, renovation and enhancements. Sometimes, general obligation bonds are also used to supplement these kinds of projects. But the funds themselves come from property taxes — and the homeowners who pay them.

Contra Costa County uses tax revenues for other purposes as well. This might include anything from wastewater management to local firefighting resources. However, local schools use the lion’s share of property tax funding. This is true for many, if not most, counties across the U.S.

Frequently Asked Questions About Contra Costa County Property Taxes

How are Contra Costa County property taxes calculated?

Contra Costa County property taxes are calculated using this formula:

Assessed Value × Total Tax Rate = Annual Property Tax

• The base rate is 1% (under Proposition 13)
• Local bond measures are added on top
• Most total tax rates fall between 1.1% and 1.3%

Example:

If you buy a home for $950,000 and your total tax rate is 1.25%, your annual property tax would be about $11,875.

Your exact rate depends on the property’s specific Tax Rate Area.

How does Proposition 13 affect property taxes?

Proposition 13 limits property taxes in California by:

• Capping the base rate at 1% of assessed value
• Limiting annual assessed value increases to 2%
• Reassessing property to market value only when it changes ownership

This keeps long-term property tax increases predictable. However, when you buy a home, it’s reassessed at your purchase price.

What happens if I miss a property tax payment in Contra Costa County?

Property taxes are due in two installments:

• November 1 (late after December 10)
• February 1 (late after April 10)

If you miss the deadline:

• A 10% penalty is added
• Additional costs may follow
• Continued nonpayment can result in a tax lien

If you have a mortgage with escrow, your lender typically pays the taxes for you.

Can I pay my Contra Costa County property tax bill online?

Yes. The Contra Costa County Tax Collector allows online payments through the county website.

You can pay by:

• E-check
• Credit card (fees may apply)

You’ll need your Assessor’s Parcel Number (APN) or property address to access your bill.

What are supplemental property taxes?

Supplemental property taxes are one-time bills issued after a property is reassessed due to a sale or major improvement.

When you buy a home, the county reassesses it at your purchase price. If the prior assessed value was lower, you’ll receive a supplemental bill for the difference. It’s an adjustment — not an additional ongoing tax.

Are supplemental taxes included in regular property taxes?

No. Supplemental taxes are separate from your regular annual property tax bill. They are typically billed directly to the homeowner and are not automatically included in your mortgage escrow account.

This is something I always review with buyers so there are no surprises after closing.

Need a Mortgage Loan in Contra Costa?

Located in Pleasant Hill, Bridepoint Funding offers mortgage services to home buyers and homeowners all across Contra Costa County. We serve the broader Bay Area as well.

Please contact us if you need a mortgage loan to buy or refinance a home in the Contra Costa area. We offer a broad range of financing options, including conventional, FHA and VA home loans.

We can give you a detailed mortgage estimate based on your specific financing needs. Just use the “Contact” link in the main menu above to get started!