Internal prototype — noindexed, not linked from public navigation yet.

Cal. EVID § 801.1

This is the official text of Cal. EVID § 801.1, part of California’s Evidence Code — sets the rules for what evidence is admissible in California courts.

Not legal advice. This page reproduces the official text of a government statute for reference only. Laws change, and how a statute applies depends on your specific facts. For advice about your situation, consult a licensed attorney in your state.

Official statutory text

(a) In a general civil case, as defined in Rule 1.6 of the California Rules of Court, where the party bearing the burden of proof proffers expert testimony regarding medical causation and where that party’s expert is required as a condition of testifying to opine that causation exists to a reasonable medical probability, the party not bearing the burden of proof may offer a contrary expert only if its expert is able to opine that the proffered alternative cause or causes each exists to a reasonable medical probability, except as provided in subdivision (b).

(b) Subdivision (a) does not preclude a witness testifying as an expert from testifying that a matter cannot meet a reasonable degree of probability in the applicable field, and providing the basis for that opinion.

Status: in_force · Read it on the official government site

Need a lawyer in California?

Find a California lawyer
About this page: Statute text is reproduced from official government publishers via the Open US Law dataset (Vaquill AI, snapshot v2026.08, CC BY 4.0). Primary legislative text like this is public domain under the government-edicts doctrine (Georgia v. Public.Resource.Org, 2020). We link every section back to its official source so you can verify it independently.