Social workers, along with their colleagues in other professions, have become increasingly aware of malpractice risks. Rumors abound about professionals who have been named as defendants in both meritorious and frivolous lawsuits. The media regularly feature stories about client-plaintiffs and patient-plaintiffs who have been awarded substantial compensatory and punitive damages based on their claims of professional negligence. The phrase litigious society has become commonplace. Despite this widespread concern, very little empirical research has been conducted on the problem of professional malpractice in social work. Several valuable conceptual discussions of the problem have been published (for example, Bernstein, 1981; Besharov, 1985; Besharov & Besharov, 1987; Kurzman, 1991). However, data on the prevalence of liability risks and their relative costs have not generally been available in the profession's published literature. This article summarizes claims data drawn from the records of the National Association of Social Workers (NASW) Insurance Trust covering the period between 1969 and 1990 (the most recent data available). Data are provided on the frequency and cost of claims for various claims categories. Suggestions are offered to minimize the occurrence of liability claims and to enhance risk management. Types of Malpractice Professional malpractice is generally considered a form of negligence. Professionals are required to perform in a manner consistent with the standard of care in the profession, legally defined as the way an ordinary, reasonable, and prudent professional would act under the same or similar circumstances (Cohen, 1979; Cohen & Mariano, 1982; Hogan, 1979; Rinas & Clyne-Jackson, 1988). Malpractice generally occurs as a result of a social worker's active violation of clients' rights (in legal terms known variously as acts of commission, or misfeasance or malfeasance) or as a result of a social worker's failure to perform certain duties (acts of omission, or nonfeasance). Misfeasance is the doing of a proper act in a wrongful or injurious manner or the improper performance of an act that might have been lawfully done (for example, inadvertent disclosure of confidential information) (Gifis, 1991). Malfeasance is the doing of a wrongful or unlawful act (for example, embezzlement of a client's funds) (Gifis, 1991). Nonfeasance is the total omission or failure of an individual to carry out the performance of some distinct duty or undertaking that he or she has agreed to do (Gifis, 1991). Malpractice occurs when there is evidence that four elements are in place: 1. At the time of the alleged malpractice, a legal duty existed between the practitioner and the client (for example, to keep treatment-related information confidential). 2. The practitioner was derelict in that duty, either through an action that occurred or through an omission (confidential information was divulged to a public welfare agency without the client's permission). 3. The client suffered some harm or injury (benefits the client was receiving were terminated after the unauthorized disclosure of confidential information). 4. The harm or injury was directly and proximately caused by the professional's dereliction of duty (the client suffered financial injury because of the social worker's unauthorized disclosure of confidential information). Some malpractice claims result from genuine mistakes or inadvertent oversight on the part of social workers (for example, neglecting to have a client sign an informed consent form) or from a deliberate decision to risk a claim (for example, a social worker decides to divulge confidential information to protect a third party from harm). In other cases, malpractice claims allege unethical behavior or professional misconduct (for example, sexual harassment of a client). Incidence of Malpractice Claims The NASW Insurance Trust sponsors malpractice coverage for approximately 60,000 NASW members. …