Time is critical in medical malpractice cases. California law imposes strict deadlines on when a claim must be filed, and those deadlines are often shorter than people expect. A claim that is filed even one day late may be barred forever, no matter how serious the injury or how clear the negligence. If you believe you have been harmed by a medical provider, understanding these limits is essential.

The General Rule: One Year From Discovery, Three Years From Injury

California's statute of limitations for medical malpractice is found in Code of Civil Procedure section 340.5. An action against a health care provider based on professional negligence must be filed within the earlier of:

Both deadlines apply at the same time, and whichever expires first controls. In practice, this means that once you suspect that a medical provider may have caused you harm, you may have as little as one year to file, even if three years have not yet passed since the treatment.

When Does the One-Year Clock Begin?

The one-year period begins when the patient discovers, or reasonably should have discovered, both the injury and its negligent cause (Gutierrez v. Mofid (1985) 39 Cal.3d 892). The California Supreme Court has explained that a claim generally accrues once a person suspects, or has reason to suspect, that someone has done something wrong to cause the injury (Jolly v. Eli Lilly & Co. (1988) 44 Cal.3d 1103). A patient does not need to know every fact or have confirmation from another doctor for the clock to start running. Suspicion of wrongdoing, combined with knowledge of the injury, is generally enough.

Limited Exceptions to the Three-Year Limit

The three-year outer limit is strict. Under section 340.5, it may be extended only in limited circumstances:

• Fraud by the health care provider;
• Intentional concealment of the negligence; or
• The presence of a foreign body with no therapeutic or diagnostic purpose or effect, such as a surgical sponge or instrument left inside a patient.

These exceptions are narrow and fact-specific. Do not assume that one applies without an attorney's review.

Special Rules for Minors

Claims involving children have their own rules. A claim on behalf of a minor generally must be filed within three years of the date of the wrongful act. However, if the child was under six years old at the time, the claim may be filed within three years or before the child's eighth birthday, whichever period is longer (Code Civ. Proc., § 340.5). These deadlines may be tolled in limited circumstances, such as fraud or collusion by a parent or guardian and the provider in failing to bring a timely claim. Parents should not assume that a child's claim can wait until the child turns eighteen. In medical malpractice cases, it generally cannot.

The 90-Day Notice Requirement

Before filing a medical malpractice lawsuit in California, the injured patient must give the health care provider at least 90 days' written notice of the intention to sue (Code Civ. Proc., § 364). If the notice is served within the last 90 days before the statute of limitations would expire, the deadline is extended by 90 days from the date of service (Code Civ. Proc., § 364, subd. (d); Woods v. Young (1991) 53 Cal.3d 315). Because the notice requirement and its effect on the limitations period are technical, it should be handled carefully and well before the deadline approaches.

Claims Against Public Hospitals and Government Providers

If the provider is a public entity or public employee, such as a county hospital, a University of California medical center, or another government-operated facility, much shorter deadlines apply. A written government claim generally must be presented within six months of the injury (Gov. Code, § 911.2). If the claim is rejected, a lawsuit generally must be filed within six months after notice of the rejection (Gov. Code, § 945.6).

Claims involving federally funded community health centers or federal facilities, such as Veterans Affairs hospitals, are governed by the Federal Tort Claims Act. An administrative claim must be presented to the appropriate federal agency within two years after the claim accrues, and a lawsuit generally must be filed within six months after the agency's final denial (28 U.S.C. § 2401(b)). Many patients do not realize that a local clinic may be federally funded, which makes early investigation essential.

Wrongful Death Claims

When medical negligence results in a patient's death, eligible family members may bring a wrongful death claim. These claims are also governed by section 340.5, and the limitations period generally begins to run from the date of death, subject to the discovery rule. Families grieving a loss should be aware that these deadlines continue to run.

Arbitration Agreements

Some health care providers and health plans, including several large health systems, require patients to sign agreements to resolve malpractice claims through binding arbitration (Code Civ. Proc., § 1295). If you signed such an agreement, your claim may need to be pursued through a demand for arbitration rather than a lawsuit, and the arbitration agreement may impose additional procedural requirements. Review any agreements you signed with your provider or health plan.

Why Acting Early Matters

Beyond the legal deadlines, there are practical reasons to act quickly. Medical malpractice cases require obtaining and reviewing complete medical records, consulting with qualified medical experts, and identifying every provider and institution involved. Under California's reformed MICRA law, determining which category each defendant falls into can also affect the amount of damages available (Civ. Code, § 3333.2). This work takes time, and it is best done well before a deadline approaches.