A husband and wife commenced this health care liability action by filing a complaint against a medical doctor and his practice. Along with their complaint, the couple filed a “Certificate of Good Faith” as required by Tennessee Code Annotated § 29-26-122(a), which requires certification that an expert has reviewed the available medical records “for the incident or incidents at issue” and that the expert believed there was “a good faith basis to maintain the action consistent with the requirements of § 29-26-115.” The original complaint alleged that the defendants caused severe permanent and physical injuries when they failed to properly diagnose and treat the husband’s cancer. After the husband died, the wife filed an amended complaint that alleged that the defendants’ negligence also caused the husband’s death. But the wife did not file a new certificate of good faith. For this reason, the defendants sought dismissal under Tennessee Code Annotated § 29-26-122(c). The trial court granted the motion, and this appeal followed. The issue is whether § 29-26-122(a) requires plaintiffs to file a new certificate of good faith with an amended complaint that alleges a new injury based on already-alleged negligent acts by existing defendants. In Sirbaugh v. Vanderbilt University, 469 S.W.3d 46 (Tenn. Ct. App. 2014) we held that a new certificate is required when adding new defendants to existing claims. And in Estate of Vickers v. Diversicare Leasing Corp., No. M2021-00894-COA-R3-CV, 2022 WL 2111850 (Tenn. Ct. App. June 13, 2022), we held that a new certificate is required when adding new allegations of negligence against existing defendants. Accordingly, we conclude that a new certificate is required when adding an injury based on existing claims against existing defendants. For this and other reasons, we affirm the trial court’s judgment in all respects.