The term "qui tam" refers to a lawsuit brought by an individual on behalf of the government. The concept of qui tam in the American legal system goes all the way back to the Civil War. In 1863, Congress enacted the False Claims Act in an effort to staunch fraudulent practices committed by individuals selling war materials to the government.
Under the qui tam provision in the FCA, a person with knowledge of a fraudulent act committed against the government can receive anywhere between 15 to 25 percent reward of money recovered if the government decides to take on the case by itself. In cases where a citizen who reports the fraudulent activity alone and then files suit without the government's assistance, he or she can receive up to 30 percent of the total amount recovered.