Delayed Cancer Diagnosis in California: Your Rights and the Statute of Limitations

When is a delayed cancer diagnosis malpractice?

Many cancers are easier to treat when they are found early. A delayed diagnosis claim usually involves a symptom, a test result or a scan that should have led to more testing and did not. Examples include a lump that was never biopsied, an abnormal lab result that no one followed up on, or a scan where a mass was missed or mentioned in the report and never passed on to the patient.

Under California’s jury instructions, a health care professional is negligent if they fail to use the skill, knowledge and care in diagnosis and treatment that other reasonably careful practitioners would use in the same or similar circumstances (CACI No. 501). The question is what a reasonably careful doctor would have done with the same information at the time, judged without hindsight about what the cancer turned out to be.

A claim also needs harm caused by the delay. If the cancer would have been treated the same way and with the same result had it been found at the first visit, there may be no case. If the delay meant the cancer spread, needed harsher treatment or could no longer be cured, that harm is what the claim is about. Our Los Angeles medical malpractice lawyer page explains the basics of every malpractice claim.

When does the statute of limitations start for a missed cancer diagnosis?

A California malpractice lawsuit generally must be filed within three years after the injury or one year after the patient discovers, or reasonably should have discovered, the injury, whichever comes first (Code of Civil Procedure 340.5). For a missed cancer diagnosis, the hard question is the date of the injury, because the missed visit and the harm can be months or years apart.

California courts hold that in a failure-to-diagnose case, the injury that starts the 340.5 periods is the first appreciable harm from the missed diagnosis, which happens when the undiagnosed condition develops into a more serious one (Drexler v. Petersen (2016) 4 Cal.App.5th 1181; Steingart v. White (1988) 198 Cal.App.3d 406). That can be well after the missed diagnosis. So a scan that was misread years ago does not always mean the deadline has passed.

The one-year period starts when you know of the injury and its negligent cause, or have information that would make a reasonable person suspect wrongdoing and look into it. You do not need to know every fact (Sanchez v. South Hoover Hospital (1976) 18 Cal.3d 93). For many patients, that is the day a new doctor says the cancer should have been caught earlier, or the day they see an old report that mentioned a mass. Our guide to California malpractice deadlines covers more examples.

Can the deadline be extended, and what is the 90-day notice?

The three-year outer limit can be extended only for fraud, intentional concealment, or a foreign object with no medical purpose left in the patient’s body. If a provider hid a test result or the fact that something was missed, that can matter, and a lawyer should look at it closely. Two other rules, explained below, can also change the deadline: the 90-day notice extension and the longer period for a child injured before age 6. Apart from these, the three-year limit holds, so waiting to see how treatment goes can be costly.

Before suing a health care provider for malpractice, you must give at least 90 days’ written notice of your intent to sue, describing the legal basis of the claim and the injuries (Code of Civil Procedure 364). If that notice is served in the last 90 days before the deadline, the filing deadline is extended, and the California Supreme Court has held this tolls the one-year period for 90 days (Woods v. Young (1991) 53 Cal.3d 315).

For children, the lawsuit generally must be filed within three years of the malpractice, but a child injured before age 6 has until three years or until the eighth birthday, whichever is later. If the doctor works for a county clinic or hospital, a separate written government claim generally must be presented within six months (Government Code 911.2), and those deadlines run alongside the malpractice deadline (Carrillo v. County of Santa Clara (2023)).

Who can be responsible for a missed cancer diagnosis?

A missed cancer can involve a primary care doctor, a gynecologist, a radiologist, a pathologist or the clinic or hospital where they worked. A hospital can be liable for an independent-contractor doctor’s negligence under ostensible agency when the patient looked to the hospital for care and was not put on notice that the doctor was not a hospital employee. In the leading case, the doctor was a radiologist who read the patient’s X-ray (Mejia v. Community Hospital of San Bernardino (2002) 99 Cal.App.4th 1448).

If your scan or biopsy was done at a hospital, you can look it up in our Los Angeles County hospital records hub, which shows each hospital’s Medicare data and state health department records. That information describes the hospital as a whole and is part of the background a lawyer reviews along with your own records. If the scan was read at an outside imaging center, ask that center for its records and the images too, since the radiologist’s group may keep its own files.

Kaiser members generally agree to binding arbitration of malpractice claims when they enroll, and Kaiser’s rules apply the same statute of limitations measured by the date the Demand for Arbitration is served (OIA Rules). The demand has to be served within the 340.5 deadline, so a Kaiser member with a missed cancer should not wait for treatment to finish before acting. Read more on our page about Kaiser misdiagnosis and delayed diagnosis claims.

How a delayed cancer diagnosis case is proved

Expert testimony is generally required in a California malpractice case to prove the standard of care, the breach and causation (CACI No. 501, Directions for Use). In a cancer case there are usually at least two physicians. One explains what a reasonably careful doctor in the same field would have done with the symptom, test or scan. An oncologist explains how the delay changed the cancer, the treatment and the outlook.

Records over time matter a great deal. Older imaging, pathology slides and lab results can show what was visible at the first visit. If you can, ask the facility to keep the original images and slides. Your lawyer may want them reviewed again by a doctor with no tie to the original provider. A second look at the same images is often how a missed finding is confirmed or ruled out.

In an injury case, the MICRA cap on non-economic damages is $470,000 per category in 2026, and one case can have separate caps for doctors and for hospitals (Civil Code 3333.2). When an award includes $250,000 or more in future damages, either side can ask the court to order those future damages paid over time (Code of Civil Procedure 667.7). Lawyer fees are capped at 25 percent before filing and 33 percent after (Business and Professions Code 6146).

If a loved one died after a missed cancer diagnosis

When a death results from medical negligence, the claim is a medical malpractice claim, and the MICRA wrongful death cap on non-economic damages applies. That cap is $650,000 per category in 2026, and up to three separate caps can apply in one case. The three-year period runs from the date of death, and the one-year period runs from when the family discovered, or should have discovered, the negligent cause of the death (Larcher v. Wanless (1976) 18 Cal.3d 646).

The claim can be brought by the surviving spouse or registered domestic partner, the children, and the children of a deceased child, and if there are none, by those who would inherit under California law (Code of Civil Procedure 377.60). Some dependents, such as parents or stepchildren, can also sue. Our page on wrongful death from medical malpractice explains who can bring the claim and how it is valued.

What to do now

Request your records in writing from every doctor, clinic, imaging center and lab involved, going back to the first visit where the symptom was raised. California patients and their representatives can inspect records within 5 working days of a written request and receive copies within 15 days (Health and Safety Code 123110). Ask for the imaging reports and the images, pathology reports and lab results.

Make a timeline: when the symptom started, each visit, what tests were ordered and what you were told. Note the day a doctor first told you the cancer could have been found earlier, because that date may start the one-year clock. Do not sign anything from a provider’s insurer before you get advice, and talk to a lawyer while there is still time to give the 90-day notice.

• Request records, images and pathology from every provider since the first symptom.
• Build a timeline of visits, tests and what you were told.
• Do not sign anything from the provider’s insurer.
• Talk to a lawyer before the one-year period runs out.

Michael Shemtoub founded Beverly Law in 2008 and has been licensed to practice law in California since 2007. He earned his law degree at UC Hastings, is admitted to practice in the U.S. District Courts for the Central and Northern Districts of California, and has tried cases to verdict. As the firm’s managing attorney, he oversees its cases.

Common questions

Related pages

California Medical Malpractice Statute of Limitations · Kaiser Misdiagnosis and Delayed Diagnosis Claims in California · Los Angeles medical malpractice lawyer

Important: This page is general information about California law, not legal advice, and reading it does not create an attorney-client relationship. Deadlines and damage limits depend on the facts of each case; talk to a lawyer about yours. MICRA amounts are for judgments, awards and settlements in 2026. Last reviewed: November 5, 2026.