In the state of California, you have two years from the date of the injury to file a lawsuit. If you wait longer than that, you run a heavy risk of not receiving compensation for all that you’ve been through. That said, the sooner you reach out to an experienced personal injury attorney, the better. The earlier an attorney gets started on your case, the greater your likelihood of receiving maximum compensation earlier than otherwise. If you mean “when to claim personal injury” in the context of “what actions must be taken,” you may have a personal injury case if you or someone you love were injured due to the negligent and/or reckless actions of another party.