Medical malpractice: 1 year from discovery of injury (CCP 340.5)

12 months after date plaintiff discovered, or through reasonable diligence should have discovered, the injury, under Cal. Code Civ. Proc. 340.5.

Rule text

In an action for injury or death against a health care provider based upon such person’s alleged professional negligence, the time for the commencement of action shall be three years after the date of injury or one year after the plaintiff discovers, or through the use of reasonable diligence should have discovered, the injury, whichever occurs first.

Cal. Code Civ. Proc. 340.5, official source

Calculate this deadline

Deadline
Monday, November 8, 2027
  1. Trigger (Date plaintiff discovered, or through reasonable diligence should have discovered, the injury): Friday, November 6, 2026.
  2. Add 12 months: Saturday, November 6, 2027.
  3. That day is a Saturday, so the deadline moves to the next court day: Monday, November 8, 2027 (Cal. Code Civ. Proc. 12, 12a, 12b; Cal. Gov. Code 6800, 6707 (state agency filings); Fed. R. Civ. P. 6(a) (federal statutes and federal court filings)).
Rules applied
Cal. Code Civ. Proc. 340.5
In an action for injury or death against a health care provider based upon such person’s alleged professional negligence, the time for the commencement of action shall be three years after the date of injury or one year after the plaintiff discovers, or through the use of reasonable diligence should have discovered, the injury, whichever occurs first.
Official source
Cal. Code Civ. Proc. 12, 12a, 12b; Cal. Gov. Code 6800, 6707 (state agency filings); Fed. R. Civ. P. 6(a) (federal statutes and federal court filings)
CCP 12: "The time in which any act provided by law is to be done is computed by excluding the first day, and including the last, unless the last day is a holiday, and then it is also excluded." CCP 12a(a): "If the last day for the performance of any act provided or required by law to be performed within a specified period of time is a holiday, then that period is hereby extended to and including the next day that is not a holiday. For purposes of this section, “holiday” means all day on Saturdays, all holidays specified in Section 135 and, to the extent provided in Section 12b, all days that by terms of Section 12b are required to be considered as holidays." Gov. Code 6707: "When the last day for filing any instrument or other document with a state agency falls upon a Saturday or holiday, such act may be performed upon the next business day with the same effect as if it had been performed upon the day appointed." FRCP 6(a): "The following rules apply in computing any time period specified in these rules, in any local rule or court order, or in any statute that does not specify a method of computing time. (1) ... (A) exclude the day of the event that triggers the period; (B) count every day, including intermediate Saturdays, Sundays, and legal holidays; and (C) include the last day of the period, but if the last day is a Saturday, Sunday, or legal holiday, the period continues to run until the end of the next day that is not a Saturday, Sunday, or legal holiday."
Official source
  • Use the EARLIER of this date and medmal_340_5_three_years_from_injury. Extended by 364(d) if the 364 notice is served in the last 90 days. Minors have separate rules (3 years from the wrongful act; under age 6: 3 years or before the 8th birthday, whichever is longer), not modeled. Claims against public-entity providers also require a Government Claims Act claim (CA-GOV).
  • If the clerk's office is closed or inaccessible on the last day (weather, emergency or local closure orders), the deadline may be extended. Check local orders.
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This calculator applies the cited rules to the dates you enter. It is not legal advice. Court orders, local rules, and case-specific facts can change a deadline; verify before relying on it. Rule set pending attorney review.

Worked example

Date plaintiff discovered, or through reasonable diligence should have discovered, the injury on Monday, March 15, 2027, personal service: due Wednesday, March 15, 2028.

  1. Trigger (Date plaintiff discovered, or through reasonable diligence should have discovered, the injury): Monday, March 15, 2027.
  2. Add 12 months: Wednesday, March 15, 2028.

Notes

Use the EARLIER of this date and medmal_340_5_three_years_from_injury. Extended by 364(d) if the 364 notice is served in the last 90 days. Minors have separate rules (3 years from the wrongful act; under age 6: 3 years or before the 8th birthday, whichever is longer), not modeled. Claims against public-entity providers also require a Government Claims Act claim (CA-GOV).

Related deadlines

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Rules current as of 2026-10-27. Confirm against the official source and any local rule or court order before relying on a date. Rules changelog.