How do I contest an insurance company's determination that I was at fault for an accident in California?

To contest an insurance company's at-fault determination, you must formally dispute the decision with the insurer by providing new evidence and, if that fails, file a complaint with the California Department of Insurance. Here is how you can contest the determination: Step 1: Request the Decision in Writing Ask the insurance adjuster for a written explanation of their fault determination. Also, request copies of all evidence they used to reach their conclusion, such as the police report, witness statements, and photos. This is your right under California regulations. Step 2: Gather Your Own Evidence Collect all documents and information that support your version of events. This includes photos or videos of the accident scene and vehicle damage, the contact information for any favorable witnesses, dashcam footage, and a copy of the official traffic collision report. Step 3: Write a Formal Rebuttal Letter Draft a clear, professional letter to the insurance adjuster stating that you dispute their finding of fault. Systematically address each point in their explanation and present your counter-evidence. Attach copies (never originals) of all your supporting documents. Send this letter via certified mail to have proof of receipt. Step 4: Escalate to a Supervisor If the adjuster does not change the decision, ask to speak with their direct supervisor or a claims manager. Calmly present your case and evidence to them, explaining why you believe the initial determination was incorrect according to the evidence. Step 5: File a Complaint with the Department of Insurance If the insurer still refuses to reconsider, file a complaint with the California Department of Insurance (CDI) online at insurance.ca.gov. The CDI will review your complaint to determine if the insurer failed to conduct a prompt, fair, and thorough investigation as required by California Insurance Code § 790.03(h). Important Details and Nuances California uses a "comparative fault" system (CA Civil Code § 1714(a)). This means fault can be shared. Even if you are found 20% at fault, you can still recover 80% of your damages. The insurer’s decision is an internal determination, not a final legal judgment. Warnings and Limitations An insurer's fault assessment is not legally binding in court. A judge or jury makes the final legal decision on fault if a lawsuit is filed. Be aware of California's statute of limitations: you generally have two years from the date of the accident to file a lawsuit for personal injury and three years for property damage. This is general information and does not constitute legal advice. For cases involving significant damages, injuries, or complex facts, you should consult with a qualified California attorney.