Property tax in Contra Costa County, California

By Brent Chudoba, editor Updated September 23, 2026

The median property tax bill in Contra Costa County, California is $7,156 a year, which is about 0.83% of the county's median home value of $866,800. That effective rate is higher than the typical California county (0.7%) and higher than the national median (0.81%). These are American Community Survey 5-year estimates (2024); your own bill depends on your home's assessed value and any exemptions.

Estimate the property tax on a home in Contra Costa County

Enter a home's market value for a ballpark at Contra Costa County's average effective rate of 0.83% (Census). The real bill depends on the home's assessed value, the millage where it sits and any exemptions.

Home market value

Estimated property tax: $7,194 / year

Property tax in Contra Costa County at a glance

Contra Costa County, California property tax (Census ACS, reviewed September 23, 2026)
Measure	Value
Median annual property tax	$7,156
Median home value	$866,800
Effective tax rate	0.83%
Typical California county rate	0.7%
National median county rate	0.81%

Effective rate = median real estate taxes paid divided by median home value. Source: U.S. Census Bureau, American Community Survey 5-year estimates.

How does Contra Costa County compare in California?

Among California's 58 counties, Contra Costa County has the 3rd highest effective property-tax rate: 2 rank higher and 55 rank lower. That places it among the most heavily taxed counties in the state. Nationally, it ranks 1499th of 3135 US counties by effective rate. See every California county ranked.

How much do homeowners in Contra Costa County actually pay?

The median is only the middle bill. Across Contra Costa County's 281,819 owner-occupied homes, 83.5% pay $3,000 or more a year in property tax, 90.7% pay at least $2,000, and 2.2% pay under $800. Another 2.5% report paying no property tax at all, which usually means an exemption covers the whole bill.

Annual property tax paid by Contra Costa County homeowners (Census ACS 2020-2024)
Annual bill	Homes	Share
Under $800	6,114	2.2%
$800 to $1,499	6,378	2.3%
$1,500 to $1,999	6,624	2.4%
$2,000 to $2,999	20,291	7.2%
$3,000 or more	235,271	83.5%
No property tax paid	7,141	2.5%

Owners with a mortgage pay a median of $7,929 and owners without one pay $5,348. Owners who have paid off a home have usually held it longer, and in states that cap how fast an existing owner's assessment can rise, long-held homes carry lower assessed values. Census table B25103.

How does the Contra Costa County property tax bill compare with local incomes?

The median property tax bill of $7,156 is about 4.6% of the median income of Contra Costa County homeowner households, $155,297 a year. That compares two middles, so a retiree in a long-held home can pay a far larger share. 68% of Contra Costa County's occupied homes are lived in by their owners; renters pay property tax too, just folded into rent.

Have property taxes gone up in Contra Costa County?

Yes. The median bill went from $5,364 in 2015-2019 to $7,156 in 2020-2024, a 33.4% rise. Over the same span the median home value moved 38.5%, from $625,800 to $866,800. Bills rose more slowly than values, which is what assessment caps and falling millage rates do: the county is taxing a smaller share of each home's worth.

Two Census ACS 5-year periods with no survey years in common, in each period's own dollars. A change counts only if it exceeds the combined 90% margin of error.

Property tax in counties next to Contra Costa County

Contra Costa County borders 7 counties.

Contra Costa County and its neighbors, highest effective rate first (Census ACS 2020-2024)
County	Effective rate	Median bill	Median home value
Contra Costa County, CA (this county)	0.83%	$7,156	$866,800
Alameda County, CA	0.78%	$8,474	$1,090,100
San Joaquin County, CA	0.75%	$3,960	$530,700
Solano County, CA	0.75%	$4,621	$617,700
Sacramento County, CA	0.73%	$3,921	$534,200
San Francisco County, CA	0.71%	$9,862	$1,394,500
Sonoma County, CA	0.7%	$5,695	$815,500
Marin County, CA	at least 0.66%	$10,000+	$1,507,300

How is a home assessed in Contra Costa County?

California sets the assessment rules and Contra Costa County applies them. How California assesses and reappraises homes.

Is there a homestead exemption in Contra Costa County?

Yes. California's Homeowners' Exemption takes $7,000 off the assessed value of an owner-occupied home. File form BOE-266 with the county assessor by February 15 for the full exemption. That is the California rule, and it applies in Contra Costa County. California's exemptions and relief programs in full.

When are property taxes due in Contra Costa County?

Secured property tax is billed in two installments: the first is due November 1 (delinquent after December 10) and the second is due February 1 (delinquent after April 10), with a 10% penalty after each. Billed and collected by the county tax collector.

California splits the bill into 2 installments. That is the California rule. Contra Costa County issues and collects the bill, so the dates printed on your statement are the ones that bind you.

How to appeal your Contra Costa County property assessment

You contest the assessed value with the County Assessment Appeals Board. The filing deadline is typically July 2 to September 15 (or November 30 in some counties). That is the California rule; Contra Costa County sets the exact dates and forms. The California appeal process step by step.

California rules from primary state sources, reviewed September 7, 2026; sources on the California page.

Work out your own numbers

Sources

Median real estate taxes paid and median home value for Contra Costa County, California: U.S. Census Bureau, American Community Survey 5-year estimates (2020-2024), tables B25103, B25077, B25102, B25119 and B25003; the five-year comparison uses the 2015-2019 estimates. Neighboring counties: Census county adjacency file.