Most civil claims are governed by a rule called the statute of limitations, which restricts the time in which a plaintiff can bring a lawsuit. Unless one of the narrow exceptions applies, a court will not hear a case in which the statute of limitations has passed. The deadline varies depending on the type of claim, and medical malpractice lawsuits usually have a specific statute of limitations that is different from other types of personal injury cases, such as car accident cases.
One reason why a medical malpractice claim may have its own statute of limitations is that the harm can be more challenging to discern. If a distracted driver hit you, or if you tripped on an uneven sidewalk, you likely have a good idea right away of how and why your injuries occurred. On the other hand, if a doctor forgot to remove a sponge after a surgery, you may not know immediately why you are suffering from certain symptoms. Or, if your doctor did not promptly diagnose a condition like cancer, you may not realize that you have the disease for years, much less that it should have been diagnosed sooner. The statute of limitations is often longer in cases involving injured children, and sometimes they even have a right to sue until they turn 18.
The Discovery Rule
To prevent doctors from escaping liability in these situations, state laws have adopted a discovery rule to protect patients. This can extend the statute of limitations when the harm was not obvious. (The discovery rule does not apply if the harm is obvious, such as if a surgeon operated on the wrong limb or made an error in cosmetic surgery that leaves your face disfigured.) In general, the discovery rule means that the statute of limitations starts to run when the patient discovers or reasonably should discover the injury.
If a patient is suffering significant pain or dealing with unexpected health conditions, they likely would be expected to seek medical treatment and investigate the cause. Patients who do not address the situation promptly will not be protected by the discovery rule. Also, the discovery rule does not override the statutes of repose that apply in many states. These categorically limit the time period in which you can bring a lawsuit. If enough time passes, a statute of repose may prevent you from bringing the claim, even if you could not reasonably have discovered the injury. Thus, there are often limits on the extent to which the discovery rule can extend the time for filing a claim.
Some states use a similar rule that applies when a patient receives a continuing course of treatment from the same doctor. If that doctor committed malpractice early in the course of treatment, the clock for the statute of limitations may start running only when the course of treatment ends, rather than when the specific incident of malpractice happened. However, this issue can be ambiguous and is frequently contested.
Raising the Statute of Limitations as a Defense
A court will not dismiss a case on its own because it was filed after the statute of limitations expired. The defendant must raise this type of procedural issue as a defense, or it will be considered waived. Most often, it is litigated early in a case in the context of a motion to dismiss, before the merits of a case are considered.