All 27 chapters in this guide
Published
- Physicians
- Attorneys
- Patients & families
Reviewed by Kanwar Partap Singh Gill, MD · sources checked
Medical malpractice is professional negligence that causes legally compensable harm. An unexpected complication, a delayed recovery, a disagreement between physicians, or an unfavorable result does not establish malpractice by itself. The central questions are what the defendant was required to do, whether the defendant failed to meet that obligation, whether that failure probably caused the injury being claimed, and what loss followed.
This guide describes California civil claims. A patient ordinarily files a civil complaint or pursues an applicable arbitration agreement; the patient does not need to obtain a Medical Board finding or file a criminal “charge” before bringing a malpractice action. Licensing discipline, a hospital investigation, an insurance claim, and a civil damages action serve different purposes and follow different rules.
The four elements
| Element | What the plaintiff must establish | What the defense will examine |
|---|---|---|
| Duty | A legally recognized obligation owed by this defendant to this patient in the circumstances. | Whether the relationship, undertaking, employment arrangement, or institutional role created the duty alleged. |
| Breach | Conduct below the applicable professional standard of care. | What information was available or reasonably should have been obtained at the time, reasonable alternatives, the defendant's actual responsibilities, and whether the criticism depends on hindsight. |
| Causation | A sufficient causal connection between the breach and the particular injury. In medical causation disputes, expert proof generally must establish reasonable medical probability. | Whether the underlying disease, another event, or an unavoidable complication explains the outcome; whether the proposed preventive intervention probably would have changed it. |
| Damages | Actual legally recoverable loss, supported by evidence. | The nature, amount, duration, and allocation of the claimed losses, including whether some existed before the alleged negligence. |
The plaintiff ordinarily bears the burden of proving the claim by a preponderance of the evidence. Duty is a legal question informed by the relevant facts. Expert testimony usually supplies the medical standard and explains departures from it, but an expert does not decide the legal scope of a defendant's duty.
California's professional standard asks whether the provider used the level of skill, knowledge, and care that reasonably careful practitioners would use in similar circumstances. A specialist is evaluated under the applicable specialist standard. The law does not require a guaranteed result or a perfect diagnostic record. It does require reasonable clinical assessment, appropriate action, and appropriate follow-through when the circumstances call for them.
A lapse must be connected to a patient injury
Consider a hypothetical abnormal imaging result that was released into an electronic inbox but never acted upon. The missed result is the beginning of the inquiry. The plaintiff must identify who had responsibility for review, what reasonable review and escalation required, and how the delay affected the patient's condition. The defense may contend that the result was routed elsewhere, that the clinician had no reasonable opportunity to receive it, or that treatment at the earlier date would not have altered the outcome.
The analysis can include both individual and institutional conduct. A physician's response to an alert and a hospital's configuration of the alert system are different factual questions. An employer's control of technology does not automatically excuse every clinical omission, and a clinician's duty does not automatically make the clinician responsible for every inaccessible setting, routing defect, or staffing decision. Policies, actual workflows, access permissions, training, escalation records, and the clinical consequences must establish the allocation of responsibility.
Medical probability, multiple causes, and lost opportunity
A causation opinion needs a reasoned explanation. It should identify the injury, the intervention that should have occurred, when it should have occurred, and why timely intervention probably would have prevented or reduced that injury. A sequence of events, an association, or a statement that a better outcome was “possible” is not enough by itself. Jennings v. Palomar Pomerado Health Systems, Inc. illustrates the problem with an expert conclusion that lacks a supported causal explanation.
There may be more than one legally sufficient cause. A defendant need not be the only contributor to an injury. Conversely, calling an omission a “substantial factor” does not eliminate the requirement to support medical causation with competent evidence.
California does not generally recognize a standalone medical malpractice recovery for a lost chance of survival that substitutes for proof that the negligence probably caused the death. Bromme v. Pavitt is a leading example. This requires careful analysis of the patient's condition at the relevant time. A population survival statistic does not necessarily answer the individual causation question. A case may also concern a separately provable injury, additional treatment, or avoidable disability rather than death alone. Counsel and experts should identify the precise injury instead of treating every delayed-diagnosis case as either automatically viable or automatically barred.
Some obvious events can support a common-knowledge or res ipsa loquitur analysis, subject to its foundation requirements. Those exceptions are narrow. They do not mean that every retained object, fall, medication event, or unexpected complication automatically establishes every element of liability.
Sources
- Judicial Council CACI 500 and 501, reproduced in the 2026 CACI collection: Essential factual elements and standard of care.
- Jennings v. Palomar Pomerado Health Systems, Inc. (2003) 114 Cal.App.4th 1108: opinion; published modification.
- Bromme v. Pavitt (1992) 5 Cal.App.4th 1487: opinion.