California Medical Malpractice Deadlines: The 1-Year/3-Year Rule

From treatment near Hollywood Boulevard to care elsewhere in Los Angeles County, a suspected medical error can take time to recognize. This guide is for patients and families trying to understand California filing clocks. It explains the one-year/three-year rule, limited tolling exceptions, and the separate pre-suit notice step without assuming that every delayed diagnosis changes the deadline.

The California malpractice deadline is an earlier-of-two-clocks rule

California malpractice claims generally face two limits at once: three years from the date of injury, or one year from when the plaintiff discovered, or reasonably should have discovered, the injury. Code of Civil Procedure § 340.5 makes the earlier date controlling. The three-year period is an outer limit, not an automatic extra three years after discovery.

The discovery clock concerns awareness of injury and reason to investigate. It does not necessarily wait until you have every record, a final diagnosis, or a professional opinion confirming negligence. At the same time, a poor outcome alone does not establish when the clock began. The facts, what you knew, and what reasonable diligence would have revealed matter.

Build a timeline before choosing a deadline. Record treatment dates, symptoms, when a new diagnosis appeared, when you first questioned the care, and explanations you received. Keep original notes and distinguish what you observed at the time from what you learned later.

If the discovery date is near the three-year mark, do not assume the one-year period provides extra time beyond the outer limit. Conversely, the outer limit does not replace the one-year period if discovery occurred earlier. Evaluate both clocks together under § 340.5.

What “discovered” can mean under the one-year period

The one-year period may begin when you actually discover the injury or when reasonable diligence should have led you to discover it. Those are separate paths. You may not know the precise medical mechanism, but facts showing an injury and reason to investigate can still matter to the start date.

Keep contemporaneous records of what you were told and when. Portal messages, discharge paperwork, referrals, second opinions, and dated personal notes can explain the sequence. Save full communications and attachments rather than cropped images; do not rewrite old notes to make them appear more certain.

The legal question is not simply when a provider admitted a mistake. Section 340.5 refers to discovery of the injury, including when reasonable diligence should have revealed it. Whether facts were enough to prompt inquiry depends on context; separate the injury date, discovery date, and first suspicion that care might be involved.

Waiting for a provider to confirm an error can be risky. You can seek an independent assessment while preserving the dates and documents that explain why. Getting more information may help assess the claim, but it does not automatically suspend the clock.

The narrow exceptions to the three-year outer limit

The three-year limit has narrow tolling exceptions under Code of Civil Procedure § 340.5: proof of fraud, intentional concealment, or a retained foreign body left with no therapeutic or diagnostic purpose. These are specific categories, not a general extension for a difficult diagnosis or a late realization that treatment may have been substandard.

Fraud and intentional concealment require proof of the conduct; disagreement with a diagnosis or an unfavorable result does not by itself establish either. Keep actual records and communications that matter. A brief summary may omit context that changes how a conversation should be understood.

The retained-foreign-body category is limited. It does not mean every implant, device, or medical item triggers an exception. The verified rule concerns a foreign body left in the body without therapeutic or diagnostic purpose; whether a particular item fits needs careful review.

Even if an outer-limit exception may apply, the one-year discovery period remains relevant. For a foreign object, discovery may occur much later depending on the facts, but that is not permission to wait. Document when the issue became known and act promptly.

Special timing questions for children and public providers

Minor patients have a special verified rule. A minor generally must file within three years of the wrongful act, while a child under six has until the eighth birthday if that period is longer. This is not a universal rule allowing a child to wait until adulthood; record the child’s age and treatment dates immediately.

A public-entity claim may add a claim-presentation deadline. A written claim generally must be presented within six months of injury or death under Government Code § 911.2; a written rejection generally creates a six-month lawsuit period under § 945.6(a)(1), while no written rejection is treated under § 945.6(a)(2). Whether it applies to a particular provider must be checked.

Overlapping deadlines should not be treated as substitutes. A public-entity deadline does not remove the need to calculate § 340.5, and a malpractice statute should not be assumed to erase a separate claim-presentation requirement. Identify the legal entity that employed or operated the provider, not just the facility’s familiar name.

If the matter involves a child, a government-operated facility, or several providers, make those facts prominent when seeking advice. The dates and party identities can change the analysis; prompt review is especially important when multiple clocks may be running.

The 90-day notice requirement is a separate step

California generally requires 90 days’ advance notice of intent to sue to the health care provider before filing a malpractice action under Code of Civil Procedure § 364. Notice is not the complaint filed in court. Keep the notice step and limitations dates on separate calendar entries.

The verified rule provides an extension when notice is served within the final 90 days of the limitations period: the deadline is extended 90 days from service. This does not make every claim deadline indefinite. Document the service date and retain proof of delivery.

Before sending notice, confirm the correct provider or other defendant. If several providers may be involved, do not assume notice to one automatically reaches all. A notice issue can affect procedure, while the underlying limitations calculation remains distinct.

Track injury date, discovery date, one-year date, three-year date, and any notice-service date. Label each by its source. This simple separation can prevent the notice period from being mistaken for a new, open-ended limitations clock.

What to do now if you suspect malpractice

You can take practical steps without deciding whether a provider was negligent. Preserve records, write a chronology, and identify each provider and facility. Keep originals unchanged; avoid discarding envelopes or messages that may show when information was sent or received.

Request the complete medical record through the provider’s ordinary process and keep the request and response. List missing periods, referrals, tests, and follow-up visits. A later review may need the chronology, not only a discharge summary.

Treat deadline calculations as provisional if the injury or discovery dates are uncertain. If a deadline may be near, seek prompt legal review rather than waiting for a full qualified medical review. Counsel can assess notice and filing steps while medical questions are investigated.

Start with this checklist:

• Record treatment, symptom, and discovery dates.
• Save complete portal messages, letters, instructions, and bills.
• List every provider, specialty, facility, and approximate care date.
• Ask whether a minor-patient or public-entity rule may apply.
• Track injury, discovery, notice, and filing dates separately.
• Do not wait for a definitive diagnosis before asking about deadlines.

Keeping the timeline useful as facts develop

Your initial calendar is a working tool, not a final legal conclusion. When a new record arrives, note when it was received and whether it changes what was known about the injury. Preserve earlier versions so a reviewer can see how the understanding developed rather than replacing entries without explanation.

If a provider later offers an explanation, save the complete communication and record its date. Do not assume that a later explanation moves discovery; § 340.5 asks when the injury was discovered or reasonably should have been discovered. Dated records make that issue easier to assess.

Where dates overlap, use separate reminders for injury, discovery, potential notice, and any public-entity claim. A reminder prompts review but does not extend a period. Share the calendar with a helper if the patient cannot manage it.

For a possible retained foreign body, preserve records identifying what was left, why it was present, and when it became known. The exception concerns a foreign body without therapeutic or diagnostic purpose; do not assume every implant or device fits.

When a child is the patient, include date of birth and alleged wrongful-act date. The under-six rule reaches the eighth birthday if longer, so a general adult calculation may mislead. Keep age facts visible in every deadline discussion.

If you are unsure whether a facility is public, record the operator name from paperwork and have its status checked. A public-entity period can coexist with malpractice timing. Do not wait for an ownership dispute to preserve the possible deadline.

Before notice or filing, verify that the chronology identifies provider, alleged injury, and recipient. A precise record is more useful than a polished but uncertain narrative. Keep source documents unchanged and link each date to its rule.

Los Angeles County context

These guides address California law for a possible malpractice injury in Los Angeles County. Most personal injury cases arising in the county are filed in Los Angeles County Superior Court and Los Angeles County Superior Court; the exact courthouse assignment should be confirmed for each case before filing. Keep the provider and facility names in your timeline, because the responsible legal entity and any public-entity status can affect the deadlines to review.