Published reports indicate that physicians sometimes use deceptive tactics with third-party payers. Many physicians appear to be willing to deceive to secure care that they perceive as necessary, particularly when illnesses are severe and appeals procedures for care denials are burdensome. Physicians whose practices include larger numbers of Medicaid or managed care patients seem more willing to deceive third-party payers than are other physicians. The use of deception has important implications for physician professionalism, patient trust, and rational health policy development. If deception is as widespread as these studies suggest, there may be serious problems in the medical profession and the health care financing systems at the interface between physicians and third-party payers. Deception may be a symptom of a flawed system, in which physicians are asked to implement financing policies that conflict with their primary obligation to the patient.