Medical Malpractice Plaintiffs May Add “Additional” Defendants Discovered Within 180 Days After Suit is Filed Pursuant to R.C. 2323.451 Without Complying with Civ.R. 15.

In Lewis v. MedCentral Health Sys., Slip Opinion No. 2025-Ohio-4802, the Supreme Court of Ohio held that, in the context of medical malpractice claims: “A plaintiff is not required to comply with Civ.R. 15(D) to name additional defendants in an amended complaint under R.C. 2323.451(D)(1), and the 180-day extension under R.C. 2323.451(D)(2) is not limited to newly discovered defendants.” Lewis at ¶1. Thus, the Court held that a plaintiff must commence a medical malpractice action within the one-year statute of limitations after the cause of action accrued pursuant to R.C. 2305.113(A), but may amend to add additional parties within 180 days of the filing of the lawsuit without complying with the Civ.R. 15(D) requirements for serving defendants whose name is unknown when suit is filed.