Fraudulent concealment means the deliberate hiding or suppression, with an intention to deceive or defraud other persons of a material fact or circumstance by a person which s/he is legally bound to disclose. For instance when a treating doctor conceals from an aggrieved patient their previous treating doctor’s malpractice, such doctor is said to have committed fraudulent concealment. Fraudulent concealment is a common law doctrine and it can be invoked to toll a statute of limitations.
In Cost Mgmt. Servs. v. Washington Natural Gas Co., 99 F.3d 937, 940 (9th Cir. Wash. 1996), the court observed that a plaintiff alleging fraudulent concealment must show wrongful concealment of action by defendants. Further a plaintiff bears ultimate burden of proving each of fraudulent concealment elements by preponderance of evidence.