What Is Discovery in a Personal Injury Lawsuit?

Discovery is the pre-trial phase of a personal injury lawsuit during which both parties exchange evidence, take sworn testimony, and identify the facts and documents that will govern the case at trial. The purpose of discovery is to eliminate surprise at trial — both sides know what evidence exists before the jury does. In California personal injury cases, discovery can span months and often consumes more time than any other phase of litigation. Understanding what discovery involves prepares injured claimants for the realistic timeline and demands of a contested personal injury lawsuit.

Types of Discovery in California Personal Injury Cases

California's Civil Discovery Act, codified in Code of Civil Procedure sections 2016.010 through 2036.050, authorizes multiple discovery tools. In a standard personal injury case, parties typically use: written interrogatories; requests for production of documents; requests for admissions; oral depositions; and independent medical examinations. Each tool serves a different purpose and generates different types of information.

Interrogatories

Interrogatories are written questions that the opposing party must answer under oath within 30 days. California Code of Civil Procedure section 2030.010 authorizes both form and special interrogatories. The Judicial Council has approved Form Interrogatories — General (DISC-001) and Form Interrogatories — Personal Injury (DISC-002) that are routinely used in personal injury cases to ask about the accident, injuries, medical treatment, prior injuries, and employment.

Defendants use interrogatories to probe: the plaintiff's version of the accident; all injuries claimed; all treating physicians and facilities; any prior accidents or injuries to the same body parts; employment history and income before and after the accident; any witnesses to the accident; and insurance coverage. Plaintiffs use interrogatories to identify: the defendant's employment at the time of the accident; insurance policies and coverage; prior similar incidents at the same location; inspection and maintenance records; and corporate structure in commercial vehicle cases.

Depositions

A deposition is oral testimony given under oath before a court reporter, outside the courtroom. The deposed witness (the deponent) answers questions from the examining attorney, with their own attorney present and able to object. The transcript is available to all parties and can be used at trial to impeach testimony that deviates from the deposition. California Code of Civil Procedure section 2025.010 governs oral depositions.

In personal injury cases, typical depositions include: the plaintiff (their account of the accident, injuries, treatment, and impact on daily life); the defendant; witnesses to the accident; treating physicians; and expert witnesses retained by each side. Plaintiff depositions are among the most important events in personal injury litigation. The defense attorney will probe the plaintiff's memory of the accident, the sequence of events, prior medical history, and current claimed limitations. Preparing thoroughly for a plaintiff deposition — reviewing medical records, timeline of events, and prior statements — is essential.

Document Requests

Requests for production of documents (RPDs) under CCP section 2031.010 require the opposing party to produce physical and electronic documents, photographs, and other tangible items. In personal injury cases, defendants typically request: all medical records before and after the accident; pharmacy records; employment records; prior accident records; tax returns (to verify lost income claims); social media content; and photographs. Plaintiffs typically request from commercial defendants: incident reports; surveillance video; inspection and maintenance logs; prior accident history at the location; insurance policies; and vehicle maintenance records in truck accident cases.

Independent Medical Examinations

As discussed in a separate article on IMEs, the defense is entitled to one physical examination of the plaintiff by a physician of its choosing under CCP section 2032. The IME generates a written report that the defense uses to contest injury severity and causation. The plaintiff is entitled to receive a copy of the IME report and to have an observer present during the examination.

Discovery Timeline in California Personal Injury Cases

California personal injury discovery typically begins within weeks of the defendant filing an answer. The parties serve initial written discovery (interrogatories and document requests) in the first few months. Responses are due within 30 days for interrogatories and document requests. Depositions are typically scheduled after written discovery responses are received, so that the deposition can probe the written responses. Expert witness disclosures are exchanged approximately 50 days before trial under CCP section 2034.210, followed by expert depositions. Discovery closes at the statutory deadline specified by the court's trial scheduling order — typically 30 days before trial.