The Department of Justice (DOJ) reports that after violent crime, health care fraud is the department's top priority. The number of health care fraud investigations pending at the DOJ increased from 270 cases in 1992 to more than 4,000 in 1997. The DOJ's primary weapon in prosecuting health care fraud is the federal False Claims Act (FCA) of 1863 (31 U.S.C. secs. 3729–3733). Almost unique among federal antifraud provisions, the FCA may also be used by “private prosecutors” to file lawsuits on behalf of the federal government charging organizations with submitting false claims to the government. The FCA rewards such whistle-blowers with a share of any resulting recoveries as a bounty and protects them from discharge for filing false claims lawsuits against their employers. It also requires defendants to pay the costs and attorneys fees of successful claimants. Although the private “bounty hunter” features of the FCA date back to the Civil War, these so-called qui tam claims were nearly dormant until 1986, when Congress amended the FCA to revive their use. Following the 1986 amendments, and paralleling the rapid increase in federal reimbursements for health care costs, private qui tam claims have far expanded beyond their traditional purview of defense contracts into the field of health care. By 1997, health care providers were the targets of 54 percent of the 530 private qui tam lawsuits filed that year.