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California · San Francisco Bay Area · East Bay · #29 Most Populous County in the US
Contra Costa County, California
Government offices, property tax appeals, public records, courts, senior services, and local resources for Contra Costa County residents
Affiliate disclosure: This page contains affiliate links. We may earn a commission if you use them, at no extra cost to you. Our editorial recommendations are independent of these relationships.
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Contra Costa County's assessment ratio means effective tax rates are low — but incorrect appraisals still cost money. Ownwell manages the appeal with no upfront cost.
How do I appeal my Contra Costa County property tax assessment?
First, call the Assessor's Prop 8 team at 925-313-7400 for a free informal review — this can often resolve the issue without a formal hearing. For a formal appeal, file between July 2 and November 30 with the Assessment Appeals Board at 1025 Escobar Street, 1st Floor, Martinez, with a $40 nonrefundable check. You must return your hearing notice indicating your intent to appear or the hearing will be cancelled. Note that the Appeals Board can increase, decrease, or affirm the assessed value — unlike some counties where only reductions are possible. Ownwell can manage the process and only charges if you save.
Where is Contra Costa County Probate Court?
The Probate Division is at the Wakefield Taylor Courthouse, 725 Court Street, Martinez. Call 925-608-1000. California probate is required when the gross estate exceeds $184,500, and statutory fees are based on gross estate value before debts.
How does Proposition 19 affect Contra Costa County homeowners?
For seniors 55 or older, Prop 19 allows transfer of accumulated Prop 13 base-year value to a new California home up to three times in their lifetime — especially valuable for long-term Lamorinda, Walnut Creek, and Tri-Valley homeowners with large Prop 13 savings. For heirs, Prop 19 (effective February 2021) limited the parent-child exclusion — children who inherit and do not use the home as their primary residence are assessed at current market value, which can mean a very large tax increase in high-value communities.
What makes Contra Costa County's assessment appeals different from other California counties?
The Contra Costa Assessment Appeals Board can increase, decrease, or affirm your assessed value based on the evidence presented. In most California counties, the board can only reduce or affirm — not increase. This means you should prepare your case thoroughly before the Thursday morning hearing. All hearings begin at 9:00 a.m. and you must confirm your intent to appear after receiving notice approximately 45 days in advance.
Office: Contra Costa County Office of Emergency Services – (925) 655-4000 | contracosta.ca.gov
Alert System: CoCo Alert; Wireless Emergency Alerts; NOAA Weather Radio; individual city alert systems
Shelter Info: Multiple shelter locations; contracosta.ca.gov/OES for current information; Red Cross coordination
FEMA Region: Region 9
Notes: East Bay county bordering San Francisco Bay and the Sacramento-San Joaquin Delta; Martinez is county seat; Hayward Fault runs through the county; Calaveras Fault; Richmond waterfront industrial hazmat (Chevron refinery – 2012 explosion injured 15,000+); Delta levee failure risk (earthquakes could breach Delta levees causing catastrophic seawater intrusion); wildfire risk in the East Bay hills (2017 Tubbs Fire did not reach CC County but extreme risk persists); sea level rise; industrial corridor along I-80 and the Bay
Roads & Utilities
ROADS & TRANSPORTATION
County Roads: Contra Costa Public Works – (925) 313-2000
Public Transit: BART (multiple lines – Richmond, Concord/Pleasant Hill, SFO/Oakland lines, eBART to Pittsburg/Bay Point and Antioch); AC Transit; Tri-Delta Transit (East County); CCTA (Contra Costa Transportation Authority); Amtrak Capitol Corridor (Martinez Station)
Notes: BART is the primary regional transit spine with multiple lines through the county; Amtrak’s Capitol Corridor (Oakland-Sacramento) stops at Martinez; I-80, I-680, I-4, Hwy 4, Hwy 242 are major freeways; the Benicia-Martinez Bridge and Carquinez Bridge cross to Solano County; the county spans from the dense Bay shoreline to the more suburban/rural East County (Antioch, Brentwood, Discovery Bay)
Business & Permits
BUILDING & PERMITS
Office: Contra Costa County Department of Conservation and Development – (925) 655-2700 | contracosta.ca.gov/dcd
Services: Unincorporated county permits; cities (Richmond, Concord, Antioch, Walnut Creek, San Ramon, Pittsburg, Brentwood, El Cerrito, Hercules, Martinez, Pleasant Hill, Pinole, San Pablo, Clayton, Danville, Lafayette, Moraga, Orinda, Pleasant Hill) have separate permits
Notes: Very active building market driven by Bay Area housing demands; East County (Brentwood, Antioch) has seen significant residential growth; transit-oriented development near BART stations; Brentwood’s ag-to-suburban conversion continues; Richmond waterfront industrial redevelopment; ADU construction throughout
Veterans Services
VETERANS SERVICES
Office: Contra Costa County Veterans Services Office – (925) 335-1500 | co.contra-costa.ca.us/veterans
VA Medical: VA Martinez Outpatient Clinic – (925) 372-2000 (significant VAMC in Martinez – one of Northern California’s major VA campuses); VA San Francisco for hospital services
Services: Full county veteran services; VA Martinez provides comprehensive outpatient services; CalVet coordination
Notes: VA Martinez is one of the Bay Area’s most significant VA campuses – a major outpatient facility serving tens of thousands of veterans; Contra Costa has a large veteran population; strong VSO chapter network throughout the county
Libraries
LIBRARIES
System: Contra Costa County Library – (925) 608-7700 | ccclib.org; 26 branches serving unincorporated areas and 9 cities; each larger city (Richmond, Concord, Walnut Creek, Antioch) has separate city library systems
Services: Books, e-books, public computers, Wi-Fi, genealogy, maker spaces, children’s programs, ESL; multilingual in Spanish, Chinese, Tagalog, Vietnamese
Notes: CCCL serves a diverse population across 26 branches; city library systems (Richmond, Concord, Walnut Creek) operate separately and are excellent; Walnut Creek’s library is well-funded reflecting the wealthy Lamorinda/San Ramon Valley demographic; East County branches serve rapidly growing suburban communities
Parks & Recreation
PARKS & RECREATION
County Parks: East Bay Regional Park District (EBRPD) – 73 parks; Mount Diablo State Park (3,849 ft – most prominently visible peak in the Bay Area; arguably the most spectacular view in California from the summit on a clear day – encompasses 40,000 sq miles of terrain from the Sierras to the Pacific); Point Pinole Regional Shoreline; Black Diamond Mines Regional Preserve (former coal mining area with remarkable history); Carquinez Strait Regional Shoreline; Lafayette Reservoir; Briones Regional Park; Las Trampas Regional Wilderness
Cities: Walnut Creek’s extensive parks; Concord Pavilion (outdoor concert venue); Martinez’s Alhambra Valley; John Muir National Historic Site (Martinez – National Park Service; John Muir’s Victorian home; the father of the American conservation movement lived here)
Notes: Mount Diablo is one of California’s most iconic peaks – on exceptionally clear days (rare) you can theoretically see from the Sierra Nevada to the Golden Gate; the 360-degree summit view is breathtaking; John Muir’s home in Martinez (John Muir NHS) is a profound pilgrimage site for American environmentalism; EBRPD’s parks throughout the county provide world-class open space remarkably close to millions of people; Black Diamond Mines’ underground coal mine history is a fascinating and little-known California story
GIS & Maps
GIS & MAPS
GIS Portal: Contra Costa County GIS – contracosta.ca.gov/gis; city GIS systems; ABAG regional planning; USGS Bay Area earthquake hazard maps; Delta levee mapping
Notes: Sophisticated GIS system; Hayward/Calaveras Fault mapping critical; Delta levee vulnerability mapping important for East County planning; sea level rise inundation mapping; Chevron hazard zone mapping; EBRPD park mapping
Animal Services
ANIMAL SERVICES
Shelter: Contra Costa Animal Services – (925) 335-8300 | ccaas.net; multiple shelter locations (Pinole, Martinez, Antioch); cities contract with county or operate separately
Notes: One of the Bay Area’s major animal services operations; active rescue and adoption community; Bay Area’s animal welfare culture drives above-average live release rates; Contra Costa Humane Society; wildlife conflicts with deer, coyotes, and turkey in suburban areas increasing
Environmental & Waste
ENVIRONMENTAL / WASTE MANAGEMENT
Solid Waste: Contra Costa County (contracted services); RecycleMore (county hazardous waste program) – recyclemore.com; each city has contracted collection
Recycling: Mandatory curbside recycling and composting under AB 1826 and SB 1383; California’s aggressive recycling requirements; RecycleMore HHW facilities
Environmental: San Francisco Bay Regional Water Quality Control Board; EPA Region 9; Chevron Richmond Refinery (largest refinery in Northern California – major air quality and spill risk; 2012 fire generated major regulatory response); USS Davis ship breaking (former naval vessels – contamination); Shell Martinez Refinery; Bay waterfront industrial contamination; Delta levee earthquake vulnerability (catastrophic seawater intrusion into Delta fresh water could affect water supply for 25 million Californians)
Notes: The Chevron Richmond Refinery’s 2012 fire (which sent 15,000 people to hospitals with respiratory symptoms) led to major regulatory reforms and hundreds of millions in refinery upgrades; Chevron Richmond is a long-running environmental justice issue – the community downwind is majority Latino and African American; the Sacramento-San Joaquin Delta levee system is one of California’s most critical infrastructure vulnerabilities – a major Hayward Fault earthquake could breach dozens of Delta levees simultaneously allowing saltwater to rush into the freshwater Delta, potentially cutting off water supply for most of California for months; this scenario is one of the Bay Area’s most catastrophic potential disasters; San Francisco Bay shoreline restoration (wetland reconstruction) is active along the Contra Costa shoreline
About Contra Costa County
Contra Costa County is California’s ninth most populous county and the twenty-ninth most populous in the United States, home to 19 incorporated cities and communities stretching from the wealthy Lamorinda communities of Lafayette, Moraga, and Orinda in the west through the industrial Richmond waterfront, the suburban Walnut Creek and Concord corridor, the upscale Tri-Valley communities of Danville and San Ramon, and the growing East County cities of Antioch, Pittsburg, Brentwood, and Oakley. The county’s economic and demographic diversity is as broad as any in the Bay Area. County government is structured around a five-member Board of Supervisors, with independently elected offices including the Assessor, Auditor-Controller, Treasurer-Tax Collector, Clerk-Recorder, Sheriff, and District Attorney. The county seat is Martinez.
All Services
Browse every category and topic available for this county.
Contra Costa County property taxes operate under California’s Proposition 13, which limits assessed value increases to 2 percent per year unless a property changes ownership or undergoes new construction. The county has seen significant appreciation across its diverse communities – from already-expensive Lamorinda and Tri-Valley neighborhoods to rapidly appreciating East County communities like Brentwood and Oakley.
The formal appeal window runs July 2 through November 30. Contra Costa County charges a $40 nonrefundable filing fee per application – mail the completed application with a $40 check to the Assessment Appeals Board at 1025 Escobar Street, 1st Floor, Martinez, CA 94553. Before filing formally, call the Assessor’s Prop 8 team at 925-313-7400 to discuss a free informal review. The Prop 8 review is particularly useful if your property’s market value as of January 1 has fallen below the Prop 13 assessed value – the Assessor can adjust it without a formal hearing.
One important difference from most California counties: the Contra Costa Assessment Appeals Board can increase, decrease, or affirm the assessed value based on evidence presented at the hearing. All hearings are scheduled on Thursdays at 9:00 a.m. Property owners receive a notice approximately 45 days before the hearing. You must return the notice indicating your intent to appear or the hearing will be automatically cancelled.
OWNWELL CTA: Are you overpaying Contra Costa County property tax? The appeal window runs July 2 to November 30. Ownwell analyzes your assessment and handles the appeal. You only pay if you save. Note the $40 filing fee.
LINK CLUSTER: How to appeal your Contra Costa County assessment, Proposition 13 explained, Prop 8 decline-in-value review (free informal), Supplemental assessment appeal, Homeowner’s exemption, Disabled veterans exemption, Proposition 19 senior transfer, Pay Contra Costa property taxes, Search your assessed value
Recommended
Are you overpaying Contra Costa County property tax? The appeal window runs July 2 to November 30. Ownwell analyzes your assessment and handles the appeal. You only pay if you save. Note the $40 filing fee.
Public Records
California’s Public Records Act gives residents access to government records held by Contra Costa County. The Clerk-Recorder maintains all recorded property documents – deeds, mortgages, liens, and official records – for the entire county. Court records are accessible through the Contra Costa County Superior Court’s Public Portal at the Tyler Tech portal. The AI assistant “Coco” on the court’s website can help navigate court resources for common questions. Arrest records are maintained by the Contra Costa County Sheriff for unincorporated county areas and by city police departments within incorporated cities.
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Search Contra Costa County public records, including arrests, court filings, property history, and background information for East Bay residents.
Search Contra Costa County arrest and court records. TruthFinder aggregates publicly available arrest records, court filings, and background information for residents across Contra Costa County.
Courts & Legal
Courts & Legal
The Contra Costa County Superior Court operates seven locations across the county to serve its geographically and demographically diverse population. The main Wakefield Taylor Courthouse at 725 Court Street, Martinez, handles civil, criminal, and probate matters. Family law is centralized at the Spinetta Family Law Center at 751 Pine Street, Martinez. The A.F. Bray Courthouse in Martinez handles criminal and jury matters. The George D. Carroll Courthouse in Richmond serves West County. The Richard E. Arnason Justice Center in Pittsburg serves East County. The Walnut Creek courthouse handles traffic and juvenile matters. Court records are accessible at 1111 Ward Street, Martinez.
Courts Directory
Court
Type
Phone
Address
Wakefield Taylor Courthouse
Civil, criminal, probate
925-608-1000
725 Court St, Martinez
Spinetta Family Law Center
Family law
925-608-1000
751 Pine St, Martinez
A.F. Bray Courthouse
Criminal, jury
925-608-1000
1020 Ward St, Martinez
George D. Carroll Courthouse
Civil, criminal, traffic — West County
925-608-1000
100 37th St, Richmond
Richard E. Arnason Justice Center
Civil, criminal, traffic — East County
925-608-1000
1000 Center Dr, Pittsburg
Walnut Creek Courthouse
Traffic, juvenile
925-608-1000
640 Ygnacio Valley Rd, Walnut Creek
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Senior Services
Senior services in Contra Costa County are coordinated through the Contra Costa County Area Agency on Aging, which serves residents 60 and older with home-delivered meals, transportation, caregiver support, in-home care coordination, the Long-Term Care Ombudsman program, and the HICAP Medicare counseling program. The Area Agency on Aging main line is 925-674-3000. Contra Costa Senior Legal Services (CCSLS) provides free civil legal assistance to residents 60 and older.
Contra Costa County’s geographic diversity creates distinct senior care landscapes. The Lamorinda and Tri-Valley communities have a concentration of high-end assisted living, memory care, and continuing care retirement communities catering to affluent seniors. Richmond and East County communities have more limited options and greater dependence on publicly funded programs including Medi-Cal and IHSS.
Proposition 19 is valuable for Contra Costa County senior homeowners 55 or older who have accumulated significant Prop 13 protection. They can transfer their base-year value to a replacement home anywhere in California, up to three times in their lifetime. This is especially meaningful for long-term Lamorinda and Walnut Creek homeowners whose Prop 13 values are dramatically below current market values.
California’s Medi-Cal program funds long-term care for eligible seniors. In-Home Supportive Services (IHSS) allows many seniors to remain in their homes with funded care assistance. Applications go through the Contra Costa County Employment and Human Services Department.
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Marriage & Vital Records
Marriage licenses, divorce records, and birth & death certificates are handled by the following office(s):
CLERK-RECORDER (Deeds, Marriage Licenses)
555 Escobar St., Martinez, CA 94553
(925) 335-7900
County Clerk
(925) 335-7800
Genealogy
County-level record sources
Contra Costa County Superior Court (marriage licenses, will and estate case files – see Probate section above)
Local societies
Contra Costa County Genealogical Society, Contra Costa County, CA
Cemeteries of Contra Costa County (research/records project)
Probate & Estate
Losing someone and having to deal with courts and paperwork at the same time is hard. This section won’t make that easier, but it should tell you what to expect, what it costs, and where to go – so at least you’re not walking in blind.
Where to go
Contra Costa County Superior Court 725 Court Street, Martinez, CA 94553 (925) 608-1000 Hours: Monday–Friday, 8:00 a.m.–3:00 p.m.
Step 1: figure out which path applies
California recently increased its small-estate thresholds substantially, so check this first – more estates now qualify to skip full probate than in past years.
Small Estate Affidavit (personal property) – for estates with personal property valued at $208,850 or less (for deaths on or after April 1, 2025; holds through March 31, 2028). No court filing needed – present the signed affidavit directly to the bank or institution holding the property. Must wait at least 40 days after the death, and no probate proceeding can already be pending.
Petition to Determine Succession to Real Property, Primary Residence – for a decedent’s primary California residence valued at $750,000 or less (Judicial Council Form DE-310). Requires a 40-day wait, notice to heirs, and a probate referee appraisal.
Affidavit for Real Property of Small Value – for other (non-primary-residence) California real property valued at $69,625 or less (Form DE-305). Requires a 6-month wait.
Formal Probate – required when the estate exceeds these thresholds. California typically uses the Independent Administration of Estates Act (IAEA), letting the personal representative handle most matters without a court hearing for each step.
California is a community property state – a surviving spouse already owns their half of community property, and can often use a simplified Spousal Property Petition (Form DE-221) instead.
If using the small estate affidavit (personal property)
Wait at least 40 days after the death.
Confirm total qualifying California personal property (excluding trust assets, joint tenancy, POD/TOD accounts, and beneficiary-designated accounts) is $208,850 or less, using date-of-death values.
Complete the affidavit under Probate Code § 13100.
Present it with a certified death certificate directly to the bank or institution – no court filing required. Collecting property this way makes you personally liable for the decedent’s unsecured debts up to the value received (Prob. Code § 13109).
IF USING THE PRIMARY RESIDENCE PETITION OR SMALL REAL PROPERTY AFFIDAVIT
Confirm the property qualifies and the applicable waiting period has passed (40 days for the primary-residence petition; 6 months for the small real property affidavit).
File the petition (Form DE-310) or affidavit (Form DE-305) with the Contra Costa County Superior Court.
A probate referee appraises the property; heirs receive notice.
Once approved, the property transfers without full probate administration.
If formal probate is required
Deliver the original will (if any) to the court clerk within 30 days of learning of the death (Prob. Code § 8200).
File a Petition for Probate (Form DE-111) to admit the will and request appointment as personal representative.
The court issues Letters Testamentary (Form DE-150) or Letters of Administration.
If Independent Administration authority is granted, the personal representative can act on most matters without separate court hearings.
Notice to creditors and an inventory/appraisal (with a probate referee) follow, along with payment of debts and taxes.
The estate closes with a final petition for distribution.
What it costs
Small estate affidavit / real property affidavits: no court filing fee for the personal-property affidavit; filing fees apply to the DE-310 primary-residence petition and DE-305 small real property affidavit.
Formal probate filing fee: several hundred dollars, varying somewhat by county.
Personal representative and attorney compensation: statutory fee schedule based on estate size (Prob. Code §§ 10800–10810) – a percentage that declines as the estate grows.
No California state estate tax or inheritance tax.
Probate filings, estate administration, and guardianship matters are handled by the following office(s):
Public Safety & Arrests
Arrest records, inmate search, and law enforcement services are handled by the following office(s):
SHERIFF
651 Pine St., 3rd Floor, Martinez, CA 94553
(925) 655-0000
Elections & Voting
Voter registration, polling locations, and elections information are handled by the following office(s):
CA Voter Registration
Health & Human Services
Offices & Contacts
Health services, social services, and assistance programs are handled by the following office(s):
Health Dept
(925) 313-6000
Social Services
(925) 608-5000
Medi-Cal
(800) 300-1506
Public Health Information
PUBLIC HEALTH
Office: Contra Costa Health Services – (925) 957-5400 | cchealth.org; Contra Costa Regional Medical Center (county public hospital)
Services: Comprehensive county health department including Contra Costa Health Plan (county HMO); immunizations; STI/HIV; environmental health; behavioral health; restaurant inspections; epidemiology
Hospitals: Contra Costa Regional Medical Center (Martinez – county safety-net hospital); John Muir Health (Walnut Creek, Concord); Kaiser Permanente (multiple sites); Sutter Delta Medical Center (Antioch); San Ramon Regional Medical Center
Notes: Contra Costa Health Services is one of California’s most comprehensive county health systems; CCRMC is the county’s safety-net hospital; Chevron refinery emergency preparedness (the 2012 Chevron Richmond fire sent thousands to hospitals with respiratory symptoms – a major industrial accident) requires specialized industrial health readiness; the county has significant health disparities between affluent western communities and lower-income East County
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