MEDICAL MALPRACTICE | 2026-09-30
Medical Battery in California: When Treatment Without Consent Is an Intentional Wrong, Not Just Malpractice
A doctor who operates without any consent — or performs a substantially different procedure than the patient agreed to — commits battery, an intentional tort distinct from ordinary informed-consent malpractice.
The right to control what is done to one’s own body is fundamental, and California law protects it in the medical setting through two distinct doctrines. Most consent claims are analyzed as <strong>informed-consent negligence</strong> — the failure to disclose the risks and alternatives of a procedu
Not every consent problem in medicine is the same. California draws a sharp line between a doctor who failed to fully inform a consenting patient and a doctor who acted without consent at all. This guide explains medical battery and how it differs from informed-consent malpractice.
Two Distinct Doctrines
California’s leading case, Cobbs v. Grant, drew the crucial distinction:
- Informed-consent negligence. Where a patient consents to a procedure but the physician failed to disclose the material risks, alternatives, or consequences, the claim sounds in negligence. The question is whether the physician met the duty of disclosure, and whether a reasonable person, adequately informed, would have declined the procedure.
- Medical battery. Where a patient gave no consent to the procedure performed, or the physician performed a substantially different procedure than the one consented to, the wrong is a battery — an intentional tort — because there was an unconsented-to touching.
Cobbs held that most consent cases belong in the negligence framework (informed consent), reserving battery for the narrower situations of no consent or a fundamentally different procedure.
When a Procedure Is a Battery
Medical battery generally arises when:
- the physician performed a procedure to which the patient did not consent at all; or
- the physician performed a procedure substantially different in nature from the one the patient authorized — for example, operating on the wrong body part, or performing an additional, unauthorized procedure while the patient is under anesthesia (absent a genuine emergency or a valid extension of consent).
The touchstone is the absence of consent to what was actually done — not merely a shortfall in the information provided about an agreed-upon procedure.
Consent Given for One Thing, Something Else Done
A common battery scenario is the patient who consents to Procedure A and awakens to find Procedure B was performed. Whether this is battery depends on how different the procedure was and whether it fell within the scope of consent (or a recognized exception, such as a true emergency that arose during surgery). A modest, expected extension may fall within consent; a fundamentally different or additional procedure the patient never authorized generally does not — and is a battery.
Why the Distinction Matters
The characterization has consequences:
- Elements and proof. Informed-consent negligence requires expert testimony about the standard of disclosure and a causation analysis (would a reasonable person have declined?). Battery focuses on the absence of consent to the act performed.
- Intent. Battery is an intentional tort; the analysis does not turn on the adequacy of risk disclosure.
- Insurance and damages. The theories can differ in how they interact with malpractice insurance, the MICRA framework, and the availability of certain damages — which is why pleading the correct theory (or theories) matters.
Emergencies and Exceptions
Consent is not always required. In a genuine emergency, where the patient cannot consent and immediate treatment is necessary to prevent serious harm, treatment without express consent is generally permitted under the emergency doctrine. Consent may also be implied or provided by an authorized surrogate. These exceptions define the boundaries of when proceeding without express consent is lawful rather than a battery.
Frequently Asked Questions
What is medical battery?
An intentional tort that occurs when a physician performs a procedure with no consent at all, or a substantially different procedure than the patient authorized — an unconsented-to touching.
How is it different from informed consent?
Informed-consent negligence involves a consented-to procedure where the physician failed to disclose material risks/alternatives; battery involves the absence of consent to what was actually done.
What case draws the line?
Cobbs v. Grant, which placed most consent cases in the negligence (informed-consent) framework and reserved battery for no consent or a fundamentally different procedure.
Is operating on the wrong site a battery?
Generally yes — performing a procedure the patient did not authorize (such as the wrong body part or an unauthorized additional procedure) is typically a battery, absent a valid exception.
Does the distinction affect my case?
Yes — the theories differ in elements, proof, intent, and how they interact with insurance and damages, so characterizing the claim correctly matters.
Can a doctor ever treat without consent?
Yes — in a genuine emergency where the patient cannot consent and immediate treatment is necessary, or with implied or surrogate consent.
Related Personal Injury Guides
Talk to a California Medical Malpractice Attorney
If a procedure was performed on you without consent — or a different procedure than you agreed to — it may be a medical battery, not just malpractice. Trembach Law Firm evaluates California consent claims. Call (818) 514-7680.
Contact Trembach Law Firm at (818) 514-7680 for a confidential consultation.
Trembach Law Firm | 27001 Agoura Road, Suite 350, Calabasas, CA 91301