Jason Sain brought a medical-malpractice wrongful-death action concerning care provided to his wife during pregnancy. More than five years after the alleged negligence, he moved to amend the pending complaint to add another physician, Audrey Arona, as a defendant. The trial court allowed the amendment, and Arona and the medical practice obtained an interlocutory appeal. The Court of Appeals reversed. Georgia’s medical-malpractice statute of repose eliminates the cause of action against an individual defendant after the statutory period expires, subject to recognized exceptions. Adding that defendant after the period has run is therefore not merely a procedural substitution; it asserts a cause of action that no longer exists. The court held that the trial court could not use the general party-amendment rule to revive the claim against Arona more than five years after the alleged professional negligence. Because the statute of repose barred the proposed claims, the order permitting the amendment was reversed.