How Do Insurance Companies Determine Who Is Liable for Injuries in California?

Many Californians picture injury claims the way courtroom dramas depict them: a judge, a jury, and dueling attorneys. The reality is quieter. The overwhelming majority of injury claims are resolved out of court, in a process largely run by insurance companies. So how do insurance companies determine who is liable for injuries in California — and what does their process mean for your recovery after a car accident or fall? Understanding the machinery is the first step to making it work for you instead of against you.

Why Insurance Companies Sit at the Center of Liability Decisions

Insurance exists because individual defendants usually can’t pay for the harm they cause. A serious injury can generate six or seven figures in medical bills and lost earnings — far beyond the net worth of most drivers or small businesses. California solves this by mandating coverage: every motorist must carry liability insurance, and businesses routinely carry premises liability and commercial policies.

The scale is enormous. The California Office of Traffic Safety reported 4,061 traffic fatalities statewide in 2023, alongside hundreds of thousands of injury crashes tracked through CHP’s SWITRS system in a typical year. Because the insurer is the party that will actually write the check, it claims the first word on who was at fault. But the first word is not the last one — that always belongs to the courts.

Inside the Adjuster’s Liability Investigation

The person who determines fault is the claims adjuster: part investigator, part negotiator, and — never forget — an employee of the insurance company.

Step 1: Gathering the Evidence

Adjusters typically begin with the police report, then layer in photographs of the scene and vehicles, physical evidence, witness statements, dashcam or surveillance footage, and medical records. Damage patterns matter more than most people realize: where the vehicles were struck, and how hard, often tells a physics story about who moved into whose path.

Step 2: Applying California Law to the Facts

Next, the adjuster maps the evidence onto the rules of the road — right-of-way at four-way stops, the duty of left-turning drivers to yield, the basic speed law, signal and lane-change violations. A driver who broke a safety statute is presumptively negligent, which is why citations in the police report are so influential.

Step 3: Assigning Fault Percentages

California follows pure comparative negligence, established in Li v. Yellow Cab Co. (1975). Fault is expressed in percentages, and each party’s recovery is reduced by their share. There is no cutoff: even a claimant found 60% at fault can recover 40% of their damages. This rule shapes adjuster behavior in a predictable way — every point of fault shifted onto you saves the company money, so expect arguments that you were speeding, distracted, or “could have avoided” the crash.

Step 4: Negotiation Between Insurers — and With You

When multiple carriers insure different parties, each may blame the other’s policyholder, producing weeks or months of informal negotiation, evidence exchange, and interviews — essentially a trial rehearsal without a judge. Only when negotiations fail does the dispute become an actual lawsuit. The tactics involved are the same ones we describe in our guide to handling insurance adjusters.

Where the Process Goes Wrong for Injured People

The system has a built-in tilt: the entity deciding fault is the entity that pays. Common results include fault percentages inflated beyond what the evidence supports, lowball valuations of legitimate injuries, and quick settlement offers made before the full scope of treatment is known. In commercial cases — a crash with a big rig, for example — the carrier may deploy rapid-response investigators to the scene within hours, while the injured person is still in the emergency room.

How an Injury Lawyer Rebalances the Equation

An attorney’s role is to keep the adjuster honest. That means independently gathering evidence before it disappears (camera footage is often overwritten within days), commissioning accident reconstruction when fault is disputed, pointing out errors in the insurer’s analysis, and presenting the damages case — current and future — with documentation the carrier can’t wave away. Most importantly, a lawyer restores the leverage the system otherwise removes: the credible ability to reject a bad fault determination and put the question to a jury. Deadlines apply — generally two years under CCP § 335.1, and just six months for government claims — so the earlier the counterweight arrives, the better. Our case results show what happens when liability disputes are contested rather than conceded.

Get a Free Case Review From a Former Insurance Defense Attorney

Miracle Law founder Tamar Miot built her early career defending insurance companies — which means she knows precisely how adjusters construct fault determinations, and where those determinations are vulnerable. If an insurer is blaming you for your own injuries, contact us for a free consultation. You pay nothing unless we win. Call (888) 843-5290.