The answer to this question is deceptively complicated. First, auto insurance claims can be divided into “first-party” and “third-party” claims. A first-party claim is a claim you file with your own insurance company (i.e. for Med Pay or UIM coverage), while a third-party claim is a claim you file under another driver’s policy (i.e. for bodily injury liability or property damage coverage). Second, while Med Pay claims do not require proof of fault, all other auto insurance claims in California do. Proving fault is complicated, and it is one of the many steps in the process that requires the involvement of an experienced San Francisco car accident insurance claim lawyer.