In 2005 CNA Insurance Companies published a Nurse Practitioners Claims Study for claims from 1994 through 2004. It reported that 81.6% (n = 523) of the claim allegations against NPs fell into the categories of diagnosis, treatment, and medication occurrences (Table 1). Additionally, 86% (n = 107) of the closed claims with indemnity payments fell within these categories.5 These identical categories, representing 82% (n = 368) of payment reports, are supported by a 14-year study by the National Practitioner Data Bank (NPDB)6 (Table 2). In short, these two studies have identified the root causes of most malpractice claims.