Pharmaceutical and medical device companies that would like to discuss off-label uses of their FDA approved products with health care professionals face a treacherous path paved with substantial uncertainty, including the threat of criminal enforcement and civil lawsuits under the False Claims Act (FCA), 31 U.S.C. §§ 3729-33. This LEGAL BACKGROUNDER will focus on recent judicial decisions on the application of Federal Rule of Civil Procedure 9(b) to FCA lawsuits against health care companies, and their potential impact on the important gatekeeper function that Rule 9(b) serves to screen out speculative complaints in cases alleging fraud.