Discovery rule

Without the discovery rule, the clock to sue would start the moment something went wrong, even if the person had no way to know about it. The classic example is a surgical sponge left inside a patient that is not found for years. Under the discovery rule, the clock does not start until the person discovers, or with reasonable care should have discovered, both the injury and its likely cause. Not every state applies the rule to every kind of claim. When it applies, the person suing usually has to explain when and how they found out about the harm.