In Washington, D.C., you generally have three years to file a medical malpractice lawsuit. This three-year period typically starts to run on the date when the negligent act or omission occurred, or when the victim discovered or reasonably should have discovered his or her injury. However, several exceptions apply. For instance, children cannot file lawsuits on their own. For this reason, the law gives child injury victims until they reach age 18 before the three-year statute of limitations period starts to run. So, generally speaking, the three-year statute of limitations will not expire until a birth injury victim reaches his or her 21st birthday.